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Evidence-based Practice in Rehabilitation: A Process for Synthesising Knowledge
Heidi Muenchberger
BBehSc(Hons) Griff MClinNeuro Macq
Submitted in fulfilment of the requirements of the degree of Doctor of Philosophy, School of Human Services, Griffith University, Brisbane January 2007
Originality of Thesis
I hereby certify that this work has not previously been submitted for a degree or diploma in any university. To the best of my knowledge and belief, the thesis contains no material previously published or written by another person except where due reference is made in the thesis itself.
__________________________________________ Heidi Muenchberger
Publications arising from or related to this Thesis
Kendall, E., Muenchberger, H., Gee, T. (2006). Vocational rehabilitation following Traumatic Brain Injury: A quantitative synthesis. Journal of Vocational Rehabilitation (in press)
Muenchberger, H. (2004). Predictors of return-to-work in rehabilitation: The usual suspects? Abstract, ‘Disability and Return-to-Work’ Conference, MidSweden University, SWEDEN, March.
Acknowledgements In completing a major work such as this, I would like to extend my sincere thanks to the people who have walked with me on this journey. To my supervisor and respected mentor, Professor Elizabeth Kendall I wish to impart my immense gratitude. Her wisdom and conceptual clarity were inspirational, and her commitment to my ongoing learning was truly valued. Professor Kendall taught me two crucial things about research - the importance of understanding ‘process’, and, to not be afraid of the dark - in the words of Thoreau, ‘to find your way by the moonlight, and see the dawn before the rest of the world’. I acknowledge the support of the Griffith University School of Human Services, Logan, and in particular, Dr Jayne Clapton and Professor Nicholas Buys who have continued to support my completion of this degree as a component of my Research Fellowship. I am also grateful for the valuable statistical advice provided by Dr Travis Gee and Dr Peter Grimbeek, who were always giving of their time. I would like to acknowledge the earlier contributions of Dr Paula Brough and Dr Mark Bahr, whose insights helped shape my arguments. To my esteemed colleagues and peers who have undertaken to review and develop my thoughts and ideas over the past four years, I extend my thanks. There is often a small army of administrative ‘worker bees’ behind a project of this nature, and the current thesis was no exception. Without their ongoing practical input, timely completion of this thesis would not have been possible. In particular, I would like to acknowledge the proof-reading services provided by Janelle Cooper and referencing work undertaken by Stephanie Prout. On a personal note, I would like to acknowledge the unconditional support provided by my friends and family throughout this endeavour. Finally, I wish to thank Alyson Locke for her encouragement and commitment.
TABLE OF CONTENTS ABSTRACT PREFACE CHAPTER 1 THE INFLUENCE OF EVIDENCE-BASED PRACTICE ON REHABILITATION ............................................................................................... 1 Rehabilitation Defined......................................................................................... 4 The ‘Evidence’ According to Evidence-based Practice ........................................ 7 Evidence-based Practice in Rehabilitation ......................................................... 10 Complexities of Rehabilitation Research......................................................... 16 Lack of Recognition of Qualitative Literature ............................................ 20 The Science-Practice Gap.......................................................................... 23 Summary........................................................................................................... 28 CHAPTER 2 THE EVIDENCE IN REHABILITATION FOLLOWING LOW BACK INJURY.................................................................................................... 30 The Nature of Low Back Injury ......................................................................... 32 Consequences of Low Back Injury ...................................................................33 Individual Consequences ........................................................................... 34 Organisational Consequences.................................................................... 36 Socio-economic Consequences................................................................... 37 The Current Evidence-Base in Low Back Injury................................................ 38 Methodological Challenges in Low Back Injury...............................................43 The Need for Longitudinal Understanding ................................................. 44 The Need for Multi-variate Understanding................................................. 47
The Need for Consistent Outcome Measurement ........................................ 49 Summary........................................................................................................... 52 CHAPTER 3 THE CURRENT RESEARCH PROGRAM .................................... 54 Undertaking a Research Synthesis ..................................................................... 56 Study One: A Narrative Systematic Review...................................................... 57 Step 1: Identification of the Research Question.......................................... 58 Step 2: Systematic Identification and Selection of the Literature ................ 59 Step 3: Reviewing the Studies..................................................................... 61 Quality Assessment ................................................................................. 63 Step 4: Critical Appraisal of Selected Studies ............................................ 64 Step 5: Synthesis of Findings ..................................................................... 64 Study Two: Determining Clinical Utility ........................................................... 69 Participants ............................................................................................... 70 Expert Panel One: University Educators................................................. 70 Expert Panel Two: Rehabilitation Practitioners ...................................... 70 Materials ................................................................................................... 73 Procedure.................................................................................................. 78 Quantitative Analysis .............................................................................. 78 Inter-rater Agreement ............................................................................. 78 Rank Ordering ........................................................................................ 81 Qualitative Analysis ................................................................................. 82 Study Three: A Meta-Ethnography .................................................................... 84 Quality Assessment .................................................................................... 87
Thematic Analysis....................................................................................... 89 Integrative Synthesis ..........................................................................................90 Summary........................................................................................................... 91 CHAPTER 4 STUDY ONE: A NARRATIVE SYSTEMATIC REVIEW ............. 92 Results: Description of the Studies .................................................................... 92 Summary of Predictors ....................................................................................93 Individual Factors ..................................................................................... 94 Demographic Factors ............................................................................. 94 Psycho-social Factors........................................................................... 101 Injury and Health Factors..................................................................... 104 Workplace Factors ................................................................................... 108 System Factors ......................................................................................... 113 Summary......................................................................................................... 115 CHAPTER 5 STUDY TWO: THE CLINICAL UTILITY OF EVIDENCE......... 129 Results ............................................................................................................ 129 Quantitative Results ...................................................................................... 129 Importance of Predictors ......................................................................... 130 Modifiability of Predictors....................................................................... 133 Clinical Relevance of Predictors.............................................................. 136 Qualitative Results ........................................................................................ 138 Summary ........................................................................................................ 143 CHAPTER 6 STUDY THREE: A META-ETHNOGRAPHY............................. 148 Results ............................................................................................................ 148
Description of the Qualitative Studies............................................................ 148 Core Theme: Personal Responses ............................................................ 151 Individual Experience ........................................................................... 151 The Meaning of Work and Injury........................................................... 153 Self-responsibility ................................................................................. 155 Core Theme: Place-based Responses ....................................................... 156 Workplace Rehabilitation...................................................................... 156 Goal-directed Interventions................................................................... 158 Graduated Return-to-Work ................................................................... 159 Core Theme: Partnerships ....................................................................... 160 Communication..................................................................................... 160 Shared Responsibility............................................................................ 162 Support ................................................................................................. 163 Collaboration........................................................................................ 164 Power Balances .................................................................................... 167 Agendas and Motivations ...................................................................... 168 Core Theme: Philosophy.......................................................................... 170 Knowledge ............................................................................................ 170 Holistic Processes................................................................................. 172 Core Theme: Policy ................................................................................. 173 Early Appropriate Intervention ............................................................. 173 Standards.............................................................................................. 174 Concluding Statement ..................................................................................... 177 Relationships Between Core Themes ............................................................. 177
Summary......................................................................................................... 179 CHAPTER 7 A CONCEPTUAL FRAMEWORK FOR REHABILITATION FOLLOWING LOW BACK INJURY ................................................................ 181 An Integrative Synthesis.................................................................................. 181 Study One...................................................................................................... 182 Summary .................................................................................................... 186 Study Two...................................................................................................... 187 Engagement............................................................................................. 189 Workplace Context................................................................................... 190 Timeliness................................................................................................ 191 Summary .................................................................................................... 191 Study Three ................................................................................................... 193 An Integrated Knowledge-base for Rehabilitation............................................ 197 The Nature of Evidence ................................................................................... 201 Conclusion ...................................................................................................... 205 REFERENCES................................................................................................ 207 APPENDIX A Detailed Search Strategy APPENDIX B Rehabilitation Practitioner Expert Panel Final List of Predictors APPENDIX C Statistical Syntax APPENDIX D Details of the Selected Studies in the Systematic Review APPENDIX E Frequency of Concepts APPENDIX F Summary of Predictors Assigned to Each Category
List of Tables Table 1: Overview of the Current Research Program ...................................... 55 Table 2: Quality Assessment Scores from Individual Studies (n=55) .............. 66 Table 3: Demographic Variables from the Rehabilitation Practitioners (Expert Panel Two) ...................................................................................... 72 Table 4: Final List of Predictors...................................................................... 74 Table 5: Key Questions Relating to Clinical Utility of Predictors.................... 77 Table 6: Kappa Values for Overall Agreement................................................ 80 Table 7: Empirical Support for Each Predictor (n=38) .................................. 119 Table 8: Patterns of Significance for Predictors ............................................ 121 Table 9: Rank Ordered Predictors Rated Consistently by Practitioners as Being Most Important to Rehabilitation (n=40) ......................................... 130 Table 10: Rank ordered Predictors Rated Consistently by Practitioners as being Less Important to Rehabilitation (n=7) ................................ 132 Table 11: Rank Ordered Predictors Rated Consistently by Practitioners as Being Most Modifiable Through Rehabilitation (n=37) ................. 133 Table 12: Rank Ordered Predictors Rated Consistently by Practitioners as Being Less Modifiable Through Rehabilitation (n=23).................. 135 Table 13: Rank Ordered Predictors Rated Consistently by Practitioners as Being Most Important and Most Modifiable to Rehabilitation (n=9)............................................................................................. 136 Table 14: Example Quotes Demonstrating the Inter-relatedness of Supportive Processes ...................................................................................... 144 Table 15: Example of Thematic Analysis in the Meta-Ethnography.............. 150
List of Figures Figure 1: Concept Map Representing the Major Thematic Domains (as indicated by circles) and Most Frequent Concept Terms................ 140 Figure 2: Conceptual Model of the Confirmed Predictors that Emerged from Study One ..................................................................................... 187 Figure 3: Conceptual Model of the Confirmed Predictors and Supportive Collaborative Processes that Emerged from Study Two.................. 193 Figure 4: Conceptual Framework of the Rehabilitation System, Predictors and Rehabilitation Processes that Emerged from Study Three............... 196
ABSTRACT The primary aim of the research was to develop a systematic process for synthesising rehabilitation evidence that incorporates both qualitative and quantitative research and clinical experience. A second aim was to use this evidence-base to develop a coherent conceptual framework for rehabilitation that can inform future interventions. These aims were articulated through the worked example of low back injury (LBI). Evidence-based practice (EBP) has received unequivocal support as a way of ensuring best practice in health and rehabilitation. However, EBP has been interpreted in a way that demands evidence conforms with stringent empirical criteria, as would typically be applied to effectiveness studies (i.e., randomised controlled trials, (RCTs)). Consequently, qualitative research and clinical experience have largely been excluded as valuable sources of evidence. However, there is some suggestion that EBP has failed to translate into improved outcomes following LBI. This thesis has argued that the relevance of EBP will be enhanced if its conceptualisation of knowledge can shift from the stringent criteria that are often applied to evidence to a more inclusive approach. The current thesis employed a program of research comprising three separate studies that contributed to the cumulative development of a coherent evidence-base. Study One systematically explored the empirical support for returnto-work predictors in the quantitative research, using the method of Narrative Systematic Review. Study Two reviewed the clinical utility of these predictors, using a method based on practitioner consultation and consensus. Study Three reviewed the qualitative rehabilitation research using Meta-ethnography. The
findings from Study One revealed 38 key predictors that were associated with return-to-work outcome following LBI. Significant empirical support was found for predictors relating to age, the subjective experience of injury and expectations of return-to-work. Trends towards significance were found in relation to workplace factors. Study Two identified nine predictors that were considered to be relevant to rehabilitation practice and, therefore, an important focus for future interventions. Study Two also demonstrated the disparity among experts in their ability to distinguish between work factors, rehabilitation processes and individual characteristics. These diverse attributions may influence practice and, therefore, outcomes. Most importantly, Study Two revealed the fact that practitioners understood predictors of outcome according to the way in which they contributed to three critical processes that underpin rehabilitation. Specifically, practitioners focused on supportive and collaborative processes that attended to issues of time, context and engagement. Study Three identified five key components that provided a framework for understanding rehabilitation as a system. Sixteen themes clustered together to form these five components, which, taken together, defined a rehabilitation system marred by tensions and multiple competing processes. Components such as policy and philosophy interacted and competed with the demands of the workplace and the individual’s personal responses. Partnerships between key stakeholders were lacking, but offered an important strategy for improving outcomes. The current thesis utilised an innovative methodology to efficiently synthesise an extensive literature base and develop clinically meaningful conclusions. This thesis has demonstrated that the knowledge cycle is an evolving
process, informed by both empirical research and clinical experience, and located within broader frameworks of understanding. It has also supported the view that evidence and its interpretation must be grounded in the context of the discipline and developmental stage of knowledge-base.
PREFACE The Endless Search for Knowledge… …wisdom from Kermit the Frog
“Why are there so many songs about rainbows, And what's on the other side? Rainbows are visions, but only illusions, And rainbows have nothing to hide. So we've been told, and some choose to believe it, I know they're wrong, wait and see. Someday we'll find it, the rainbow connection, The lovers, the dreamers and me. All of us under its spell, we know that it’s probably magic, Who said that every wish would be heard and answered, When wished on the morning star? Somebody thought of that, and someone believed it, And look what it's done so far. What's so amazing that keeps us stargazing, And what do we think we might see? Someday we'll find it, the rainbow connection, The lovers, the dreamers, and me. All of us under its spell, we know that it’s probably magic.” (Jim Henson, Creator of the Muppets)
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CHAPTER 1 So Many Songs About Rainbows THE INFLUENCE OF EVIDENCE-BASED PRACTICE ON REHABILITATION
Over the past two decades, evidence-based practice (EBP) has transformed the way practitioners, researchers, policy makers and consumers view health research. National and State funding bodies now strongly encourage health practitioners to adopt practices that are firmly grounded in evidence (Braslow, 1999). Indeed, there is considerable pressure on practitioners to demonstrate that their rehabilitation practice is grounded in the best available evidence. This emphasis on EBP has forced rehabilitation researchers to produce evidence that meets stringent criteria (i.e., randomised controlled trials (RCTs)), based on the assumption that such evidence will produce better practice and improved outcomes. EBP has been viewed as a particularly important development because it has the potential to facilitate the likelihood of improved outcomes from costly rehabilitation interventions (Bond et al., 2001). In recent years, however, some critique of EBP has emerged. Specifically, it has been observed that the scientific paradigm that underpins EBP can limit our understanding of complex processes such as rehabilitation (Clarke, 1999; Eakin & Mykhalovskly, 2003). As a result of this dominant paradigm, significant bodies of research have been excluded from the evidence-base (i.e., valuable multi-variate and longitudinal predictive studies, qualitative research and clinical experience). The overly stringent interpretation of EBP that derives from the scientific
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paradigm has resulted in a narrow approach to the collation and application of evidence and a continued divide between knowledge and its clinical application. There is an extensive body of rehabilitation research that could potentially guide rehabilitation interventions. Yet much of this research has been excluded from consideration due to the fact that it does not comply with the stringent EBP criteria. The narrow definition of evidence that is used in EBP has meant that rehabilitation researchers have been unable to construct a convincing evidencebase for the discipline. Indeed, the evidence-practice gap remains highly problematic in rehabilitation. Given that the rehabilitation process is complex, dynamic, individualised and context-specific, it is necessary to explore the determinants1 of outcome following work-related injury. This evidence can then guide the development of future interventions. However, understanding of the complex determinants of outcome cannot be achieved through experimental designs only, as would be prescribed by stringent EBP criteria. There is clearly a need for an alternative, yet systematic, approach to the synthesis of existing evidence that will enable rehabilitation researchers to create a coherent conceptual framework to guide the future of the discipline. The current thesis has two aims. The primary aim of the research is to develop a systematic process for synthesising rehabilitation evidence that incorporates both qualitative and quantitative research and clinical experience. A second aim is to use this evidence-base to develop a coherent conceptual framework for rehabilitation that can inform future interventions. These aims are
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The terms determinants, factors, and prognostic indicators are used interchangeably and inconsistently in the literature. For this thesis, the term ‘determinants’ is used as a non-specific reference of predictors of outcome. The term ‘factors’ is generally used in this thesis to refer to a collection of predictors.
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articulated through the worked example of low back injury (LBI). LBI is a costly cause of disability in most industrialised countries and is often associated with variable and confusing return-to-work outcomes (Dionne, Koepsell, Von Korff, Deyo, Barlow & Checkoway, 1997). LBI is characterised by complexity (Feuerstein & Beattie, 1995; Marras, 2000) and, despite the fact that it has been researched extensively, it remains relatively misunderstood by rehabilitation practitioners (Shaw, Pransky & Fitzgerald, 2001). There are seven chapters to this thesis. The current chapter investigates the broad concerns related to EBP, namely, the nature of evidence in rehabilitation and the issues associated with applying an evidence-based paradigm to rehabilitation research and practice. The next chapter provides an overview of LBI to illustrate the complexity of rehabilitation and the need to develop a comprehensive and clinically meaningful evidence-base. Chapter 3 explores the methodological issues associated with the development of an evidence-base and outlines the multi-stage synthesis methodology that will be applied in this study to expand the knowledge about rehabilitation. The next three chapters each present one study that forms part of the overall approach to evidence that will address the aims of this thesis. Specifically, Chapter 4 describes the results of a narrative synthesis of the quantitative literature to identify predictors of return-to-work outcome. Chapter 5 describes the results of an innovative study designed to engage practitioners in the process of evidence development, thus increasing the clinical utility of the findings. Chapter 6 describes a synthesis of the qualitative literature about return-to-work rehabilitation. The final chapter integrates the findings of these multiple studies and develops a conceptual framework to guide
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rehabilitation interventions in future. The chapter discusses the process of knowledge synthesis that was adopted in this thesis and its implications for EBP in rehabilitation. In the current chapter, the impact of EBP on rehabilitation is explored. First, rehabilitation is defined and the use of EBP in rehabilitation is examined. This section includes an overview of the origins of EBP, and the way in which evidence has been conceptualised in EBP protocols. The issues raised by the application of EBP in rehabilitation are then presented. Following this discussion, it will be concluded that the stringent interpretation of evidence that dominates EBP is insufficient to address the need for knowledge about a complex field such as rehabilitation. A broader conceptualisation of evidence is presented that combines both quantitative and qualitative research and integrates clinical judgement into the development of knowledge. The chapter proposes the need for a method that overcomes the limitations created by the current conceptualisation of EBP if meaningful and comprehensive knowledge about rehabilitation is to be developed.
Rehabilitation Defined Rehabilitation is an important post-acute health care strategy aimed at ameliorating the impact of injury, expediting return-to-work and promoting quality of life. According to the Australian Government (Disability Services Act, 1986), a rehabilitation program may include employment and vocational training, educational courses and programs, mobility and other independent living training; diagnostic and assessment services, occupational therapy, physiotherapy, speech
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therapy, and counselling and social work services; accommodation, transportation and personal support services; prostheses and aids, including home, vehicle and work-place modifications and the provision or modifications of appliances, equipment, books, or tools of trade. These services are delivered in order to produce a substantially increased capacity to obtain or retain paid employment (whether or not that employment is unsupported) or live independently. Successful return-to-work is an important outcome of rehabilitation as it promotes the active recovery of the injured worker, reduces the impact created by work absence and, consequently, lowers compensation premiums for employers (MacEachen, Clarke, Franche & Irvin, 2005). At the individual level, the significance of maintaining work is undeniable. In addition to contributing to financial well-being, the value of work can be seen in its impact on self-esteem and social connections (Dongen, 1996). Work also offers a protective buffer for individuals who are trying to manage a serious injury or illness (Mason, Carey, Jaskulski & Stukey, 1995). Early research conducted by Maslow (1968) suggested that work not only fulfils basic human needs (i.e., security, food and shelter), but also facilitates the attainment of higher level needs, such as competence, meaning and social interaction. Given that a person’s identity is shaped by their experience of work, the loss of work represents considerable disruption to health and wellbeing. Indeed, unemployment and reduced work participation have been directly associated with mortality and morbidity, increased health service utilisation (Mathers & Schofield, 1998), psychological and physiological distress and the diminution of social networks (Dongen, 1996; Elliott, 1996).
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Despite the importance of returning to work and increasing work participation following injury, research has suggested that rehabilitation may not have met expectations in this regard (Kendall, Muenchberger & Clapton, 2006). In one of the largest surveys of injured workers ever conducted (i.e., 11 000 injury compensation cases), researchers found that although the initial return-to-work rate following injury was close to 85%, this rate fell by almost half in the longterm (Baldwin, Johnson & Butler 1996). For some injury groups, (i.e., musculoskeletal injury), the incidence of injury has remained stable over the past decade, but the rate of disability (i.e., individuals with prolonged symptoms who claim workers compensation) has increased (Molloy, Blythe & Nicholas, 1999). However, at the same time, the rate of rehabilitation service delivery for injured workers has doubled, suggesting that increased rehabilitation input may not always equate to improved outcomes (see Kendall et al., 2006 for a review). This conclusion does not reflect well on the efficacy of rehabilitation services and casts doubt on the legitimacy of the growth that the rehabilitation industry has enjoyed over the same time period (Kendall & Clapton, 2006). In an effort to improve outcomes following rehabilitation, researchers in the late 1980s called for a better understanding of the determinants of low back injury outcome (Deyo & Deil, 1988). By targeting rehabilitation interventions around key risk factors, it is likely that prolonged disability could be prevented. Importantly, it was found that for every dollar spent on targeted and timely rehabilitation, up to US$30 in future costs could be saved (Shaw et al., 2001). However, in excess of 100 determinants of return-to-work have been identified in the back injury population (Krause, Frank, Dasinger, Sullivan & Sinclair, 2001),
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leaving the rehabilitation field with little certainty upon which to base intervention decisions. Clearly, a useful and accessible evidence-base would facilitate improved rehabilitation strategies and better return-to-work outcomes.
The ‘Evidence’ According to Evidence-based Practice Evidence-based practice (EBP) is a term that has derived from evidencebased medicine. Seminal research conducted by Sackett and colleagues in the mid 1990s defined evidence-based medicine as “the conscientious, explicit and judicious use of current best evidence in making decisions about the care of an individual patient” (Sackett, Rosenberg, Muir Gray, Haynes & Richardson, 1996, p. 71). According to evidence-based medicine, ‘evidence’ pertains primarily to knowledge that is derived from quantitative sources, and can be objectively measured (Rycroft-Malone, Seers, Titchen, Harvey, Kitson & McCormack, 2004). Other researchers have defined ‘evidence’ as empirical data originating from “formal research or systematic investigations, using any type of science or social science methods” (Rychetnik, Frommer, Hawe & Shiell, 2002 p. 119). EBP has also adopted this narrow definition of ‘evidence’, meaning that this approach has influenced many other disciplines, including rehabilitation. Evidence-based medicine was established principally in reaction to the overload of information in medical research (Ter Meulen & Dickenson, 2002) and pressure to validate clinical decisions (Gambrill, 2003). The approach of evidence-based medicine offered a strong scientific foundation for clinical practice, and provided a foundation from which to ensure effectiveness, efficiency and quality in patient care (Timmermans & Mauck, 2005). Before the introduction
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of evidence-based medicine, clinical judgements were inconsistent and were often based on a range of assumptions and experiences rather than reliable evidence (Timmermans & Mauck, 2005). The margins of error in clinical judgements and the potential impact of poor judgements were considered to be sufficient to warrant a change in practice, from decisions informed by clinical experience and precedence to decisions based upon sound scientific evidence (i.e., objectifiable data). The impact of EBP on rehabilitation has been profound, in that it has determined the nature of service delivery and has influenced the philosophy that underlies rehabilitation practice. The impact of EBP quickly becomes apparent by reviewing the latest research guidelines published by the statutory authority for research in Australia, the National Health and Medical Research Council (NHMRC). The most recent research guidelines disseminated via the official NHMRC website (National Health and Medical Research Council, 1999) focussed primarily on EBP. (e.g., Reviewing, preparing and presenting evidence, putting evidence into practice, analysing costs and benefits, using socioeconomic evidence, developing clinical practice guidelines and so forth). Protocols for establishing scientific evidence and rigour were developed in line with the original intent of EBM, which was to “de-emphasise institutionalised, unsystematic clinical experience, and pathophysiologic rationale” in clinical decision-making (Whitstock, 2003, p. 214). EBP protocols were established and widely disseminated by authoritative bodies (e.g., The Cochrane Collaboration). According to these protocols, decisions about treatment needed to be contingent upon the presence of sufficient high quality evidence to
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support the efficacy of that treatment regime (Graham, Beardall, Carter, Tetroe & Davies, 2003). Thus, concerns about disparity and bias in clinical practice were addressed by linking practice to research that had been filtered through a standardised quality classification system (Timmermans & Mauck, 2005). EBP was based on a hierarchical classification of research quality, founded on the conclusion that particular types of research constituted the most unequivocal evidence of effectiveness. The hierarchy of evidence ranged from Level One to Level Five (Sackett, Strauss, Richardson, Rosenberg & Haynes, 2000). Specifically, Level One evidence was a synthesis of ‘best-evidence’ (i.e., a systematic review or meta-analyses that integrated multiple randomised controlled trials (RCT) of the highest rigour). Summary or synthesis methods such as these were developed to systematically appraise the accumulation of independent high quality intervention studies (Anthony, Rogers & Farkas, 2003; Graham et al., 2003; Hawker, Payne, Kerr, Hardey & Powell, 2002). The intention of the systematic review process was not only to collectively scrutinise the effectiveness of an intervention, but also to identify gaps in research evidence, guide policy, inform future decision making, and assist in allocating resources (Fox, 2005; NHMRC, 1999). Level Two evidence related to individual RCTs that may be later selected for inclusion in a systematic review. Not all controlled trials will meet the inclusion criteria for a systematic review, but can still provide reliable and valid evidence on which to base clinical judgements. In fact, most meta-analyses typically exclude a large proportion of published studies (e.g., it is not uncommon for over 95% of identified articles to be excluded) (see Turner, McClure &
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Pirozzo, 2004), leaving only a small subset of the original literature on which to base clinical judgements. Although Level One and Two evidence is considered to be the ‘gold standard’ in EBP, the potential contribution of other types of evidence has also been recognised. Levels Three, Four and Five describe quasi-controlled and nonrandomised studies, descriptive studies and expert opinion (Anthony et al., 2003). However, these levels of evidence are typically considered ‘weak’ or ‘poor’ relative to the more robust evidence produced through Level One or Two research (Contopoulosloannidis, Gilbody, Trikalinos, Churchill, Wahlbeck, & Ioannidis, 2005). It has also been acknowledged by the Oxford Centre for Evidence-Based Medicine (CEBM) that other critical research questions emanate from clinical practice, the answers to which are important in determining interventions and outcomes, but demand a different type of evidence (Oxford Centre for EvidenceBased Medicine, 2001). These questions concern the prevalence or prognosis of particular conditions, illnesses or injuries and the factors that can determine such outcomes. Such quantitative questions necessitate research designs that rarely meet Level One or Two criteria. Nevertheless, the same protocols have been uniformly applied to these research designs creating a situation where valuable evidence is disregarded and clinically relevant conclusions remain elusive.
Evidence-based Practice in Rehabilitation Although developed from a medical framework, the evidence-based approach offers a great deal of potential for rehabilitation and the social sciences,
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at least as a procedure for establishing a strong research framework from which to initiate change. Over the past decade, several health disciplines, including rehabilitation, have made significant shifts from intuitive and experience-based practice to a position which advocates the use of EBP. The appeal of this shift has been the promise that rehabilitation interventions can be selected because they have been demonstrated to be effective (Anthony et al., 2003; Appleby, Walshe & Ham, 1995; Torrey et al., 2001). A major force underlying this shift in rehabilitation practice has been the interpretation by National and State funding agencies that in order to find viable solutions to expensive health problems, rehabilitation must be based on evidence of effectiveness. As a result, major government and non-government authorities have urged practitioners to only adopt practices that are reinforced by a stringent form of scientific and quantifiable evidence (Braslow, 1999). Rehabilitation practitioners have largely complied with the demand that their interventions be grounded in scientific evidence and have, therefore, sought Level One and Two research findings. Decisions about how services are delivered now largely depend on the amount of scientific evidence that is available (Claxton, Cohen & Neumann, 2005). At first glance, the application of strict EBP protocols and the judicious review of scientific evidence to inform funding and service decisions would appear to be a necessary strategy. However, there is some suggestion that policy makers may have over-interpreted the importance of the evidence hierarchy that has underpinned EBP. As a result, an assumption has been made that the only sources of evidence upon which to base service funding decisions are RCTs and
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similar experimental research designs (Anthony et al., 2003; Rose, Thornicroft & Slade, 2006). In accounting for this interpretation, it is important to note that EBP is a reflection of the ongoing dominance of the scientific paradigm in health research. The scientific paradigm emphasises testable and measurable observation, typically through quantitative data and experimental designs, such as RCTs. This approach has long been considered to be the only legitimate way of doing research (Heffner, 1998) and has informed the development of EBP as the “new paradigm for medical practice” (Evidence-Based Medicine Working Group, 1992, p. 2421). The domination of the scientific paradigm has precluded the collation of other sources of evidence, many of which could address the fundamental questions that confront rehabilitation practitioners in their search for knowledge to guide practice. Kuhn (1959) believed that paradigms were essential to scientific enquiry in that “no natural history can be interpreted in the absence of at least some implicit body of intertwined theoretical and methodological beliefs that permit selection, evaluation, and criticism” (pp. 16-17). He described paradigms as both a way of defining scientific problems and a robust framework for defining the range of admissible evidence that may influence a solution. The notion of the ‘scientific paradigm’ was founded on the positivist beliefs of the 1920s and 1930s. Around this time, German philosophers posited that science should restrict itself to testable outcomes, and only scientific statements that could be shown to be conclusively true or false were considered meaningful (Hunt, 1991). Notwithstanding the vast literature on the nature of reality and truth (Fossey,
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Harvey, McDermott & Davidson, 2002), the basic assumption of this belief was that real causes exist, are predictable and could be observationally tested, independent of an individual’s perception (Devers, 1999). This positivist approach is synonymous with quantitative research to the exclusion of qualitative research (Deshpande, 1983). Although it is a natural progression for a dominant paradigm to permeate all areas of practice, it has been suggested that the more a paradigm moves away from its original context, the less utility it has without modification (Hairston, 1982). Easy problems that comply with dominant paradigms are solved first, whereas non-compliant problems that challenge the paradigm remain unanswered (Sterman, 1982). Kuhn (1970) suggested that when complying with a particular paradigm, research becomes “an attempt to force nature into the preformed and relatively inflexible box that the paradigm supplies” (p. 24). Thus, a pervasive trend can develop in that the majority of people working within a particular field abide by the prevailing paradigm, ignoring contradictions and inconsistencies, and making ad hoc changes in practice to cope with the immediate challenges (Hairston, 1982; Sadler & Hulgus, 1991). Without innovative and creative input, paradigms tend to become increasingly redundant. However, paradigms are inherently robust, meaning that the dominant paradigm is likely to remain ascendant and will be expected to solve increasingly complex problems (Kuhn, 1970). The dominant paradigm is likely to remain unquestioned until such time as overwhelming evidence has accumulated to expose a gap between data, theory and practice and cast doubt on the suitability of a prevailing framework (Kendall & Clapton, 2006).
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In the case of rehabilitation, this gap is beginning to emerge. As a discipline, rehabilitation is characterised by complexity, variability over time, is grounded in the individualised context of the client and is responsive to the demands of a complicated environment. In contrast, EBP values research that simplifies and controls the environment in accordance with the scientific paradigm. This approach fails to accommodate full expression of the complexity of rehabilitation. Consequently, it is plausible that rehabilitation knowledge may not be advanced unless research can extend beyond the scientific paradigm and embrace other types of evidence that can provide answers to complex problems. In the rehabilitation context, the dominant scientific paradigm has limited the ability of rehabilitation practitioners to address prevailing concerns in the area. What is needed to address these increasingly complex concerns is an expanded view of what constitutes relevant evidence within rehabilitation research. Some doubts have begun to emerge about the rightful dominance of the positivist scientific paradigm (Phillips, 1987). Even early researchers, such as Brodbeck (1968), argued that “quantification is not a necessary or sufficient condition for science” (pp. 573 – 574). This shift was further articulated by the emergence of beliefs that realism was not only defined by measurable outcomes, but could include subjective attitudes, intentions and beliefs (Hunt, 1991). This post-positivist approach to research which emerged in the 1950s and 1960s, has continued to develop. Many researchers now acknowledge the need to move away from the dominant scientific paradigm, to incorporate multiple views and approaches in conceptualising what constitutes research evidence. The resulting multi-dimensional approach is defined by the concept of ‘pluralism’,
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which is a tolerant, open mindset towards new theories and knowledge (Hunt, 1991; Sadler & Hulgus, 1991). Despite the rise of this inclusive understanding of what constitutes a meaningful and appropriate science, the principles of observable realism continue to influence and drive EBP. The dominance of the scientific paradigm and its influence on the development of EBP has had several important ramifications for rehabilitation. First, the dominance of the scientific paradigm has reduced the ability of rehabilitation to produce a credible evidence-base. The inherent complexities in the rehabilitation environment mean that the process of conducting RCTs and complying with narrow definitions of the scientific paradigm is challenging, if not impossible. Although rehabilitation is a complex, multifaceted process, EBP has forced rehabilitation researchers to focus on research that can be easily measured and quantified. Ironically, this situation has lead to the absence of evidence rather than the improvement of evidence. Second, due to the strict interpretation of EBP protocols, qualitative research has been under-valued and under-utilised. Thus, research about subjective experiences, social processes and contextual or systemic factors has less likelihood of being reflected in the evidence-base (RycroftMalone et al., 2004). Third, EBP is based on an assumption that evidence will be translated into practice, thus bringing about improvements in service delivery. However, rehabilitation practitioners have difficulty accessing and engaging with research, resulting in an enduring science-practice gap. Each of these implications of EBP is discussed in more detail in the following sections.
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Complexities of Rehabilitation Research Rehabilitation research has been plagued by several inherent methodological problems that minimise the ability to apply EBP protocols. These problems include, but are not limited to, (1) the heterogeneity of the rehabilitation context, workers and clients, (2) unpredictable recovery patterns and the complex processes that effect adjustment, (3) the lack of sensitive measurements to assess the more subtle outcomes of the rehabilitation processes and (4) small effect sizes, presumably due to the attenuating impact of small samples and inflated withingroup variability (Krause et al., 2001; McAweeney, Forchheimer & Tate, 1997). With regard to the heterogeneity of the rehabilitation context, rehabilitation provided at the post-hospital phase (i.e., tertiary rehabilitation phase) generally lacks homogeneity in that interventions are usually individualised programs, tailored to client needs rather than medical frameworks (Bryant & Bickman, 1996). Moreover, rehabilitation personnel tend to originate from a diverse range of disciplines and experiences, leading to vastly different conceptualisations of rehabilitation. Thus programs can be implemented in a variety of ways as determined by the client’s context, and the workers background. To complicate this picture, there are no clear pre-disposing factors that might determine the characteristics of the population most likely to sustain injury. Although some tentative conclusions have suggested that age, gender and employment history may contribute to injury there is no standard pattern of causation in LBI and rehabilitation interventions are applied to a diverse population (Leboeuf-Yed, Lauritsen & Lauritzen, 1997). Further, the nature,
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extent, and degree of injury can vary enormously between individuals. Consequently, the rehabilitation population can be expected to have greater heterogeneity than might be found in many other clinical populations (High, Boake & Lehmkuhl, 1995). Emphasis on the internal validity of a trial, as is the case in RCTs, effectively excludes cases that are complex and therefore potentially obscure the results of efficacy studies. As argued by de Costa (1999), cases may be selected out because they represent extreme disadvantage or disability (e.g., too sick, long term unemployed or non-compliant with rehabilitation). This selectivity results in the evaluation of an intervention that would otherwise be intended for the very population it excludes. Further, excluded cases tend to have a worse prognosis than those included, making conclusions about generalisability unattainable (McKee et al., 1999). Heterogeneity contributes to a research environment that is high in background noise. This noise cannot be easily monitored, eliminated or minimised, thus preventing researchers from establishing desirable levels of control. Additionally, given the fact that there are many prognostic factors, differences between groups would be expected despite randomisation (Novack, Bush, Meythaler & Canupp, 2001). In addition to the ‘noise’ created by variability, rehabilitation must confront more serious problems that could limit the value of efficacy studies in this area. Specifically, individuals with injury often demonstrate unpredictable periods of spontaneous recovery or exacerbation that are likely to have little to do with rehabilitation interventions. Indeed, it is not unusual for people with injury to experience sporadic and unpredictable changes in their functioning over the first
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few years (High et al., 1995). Such changes can be the result of a combination of physiological processes, psychological adjustments, social changes or environmental modifications and may have no association with rehabilitation interventions. This situation leads to an unpredictable profile among rehabilitation clients and difficulty in attributing changes to particular factors or rehabilitation interventions. Under these circumstances, the need for control groups is heightened, a requirement that cannot easily be met within rehabilitation populations due to heterogeneity, small sample sizes and biased referral processes (Anthony et al, 2003). To complicate this situation, vocational rehabilitation research has been plagued by issues of inconsistent outcome definition and measurement insensitivity. In particular, tertiary rehabilitation programs are not focused on objective and quantifiable changes in outcome (Chmura-Kraemer & Thiemann, 1987), such as physical performance or tissue growth. Instead, vocational rehabilitation is typically concerned with ‘fuzzy’ outcome constructs, such as performance in the workplace quality of life, psycho-social well-being and social acceptance. Outcomes in vocational rehabilitation are obscured by the complex interplay of medical, psychological, social, and community factors and, thus, are unlikely to conform to simple linear predictive models that can be tested in controlled research designs (McAweeney et al., 1997). These outcomes are likely to be defined in a multitude of ways depending on the individual researcher’s opinion. As Brooks, McKinlay, Symington, Beattie and Campsie, (1987) cogently noted, meaningful rehabilitation research has been substantially hindered by the
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absence of a consistent approach to the operational definition of outcome because results are rarely comparable. The subtle but pervasive changes that are associated with rehabilitation can be difficult to articulate and instruments often lack the sensitivity required to detect such changes. Further, rather than directly impacting on outcome, it is possible that rehabilitation may have its greatest impact indirectly by preventing negative outcomes. Consequently, the efficacy of rehabilitation may be best assessed via the opportunity-cost of not intervening (Browne, Arpin, Corey, Fitch & Gafni, 1988), a concept that is extremely difficult to research using traditional designs and reinforces the need for well-matched control groups. These ‘soft’ outcomes will exacerbate the difficulty associated with small effect sizes and low statistical power (Chmura-Kraemer & Thiemann, 1987), two qualities that are typically essential to EBP research. As a result of the attenuating impact of measurement difficulties, small sample sizes and inflated variability (McAweeney et al., 1997), rehabilitation outcome studies tend to demonstrate only small to moderate effect sizes. Thus, many factors may be considered less significant simply due to power issues rather than any inherent lack of utility. Given the inherent complexities of the rehabilitation environment, it is unlikely that “single experiments or studies provide sufficient definitive answers upon which to base policy” (Wolf, 1986, p. 9). Although some researchers have gone so far as to suggest that null-hypothesis statistical testing has less place in rehabilitation than judgements about clinical significance (McAweeney et al., 1997), the issue of low power could be partially
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addressed through the synthesis of multiple studies, the refinement of outcome constructs and measurement techniques to enhance sensitivity to change. Lack of Recognition of Qualitative Literature As a consequence of the reliance on experimental, ‘hard’ scientific ways of thinking, some rehabilitation researchers have become intolerant to the idea of ‘soft’ qualitative evidence (Clarke, 1999). Yet, health systems are in and of themselves inherently multifaceted, wherein system complexity is characterised by non-linear interactions, with networks of open feedback-loops and include populations in which people influence each others’ behaviour across time and in unpredictable ways (Gatrell, 2005). Therefore, linear, experimental models cannot be used to measure a non-linear, chaotic system. Qualitative research is a “research methodology that describes and explains the person’s experiences, behaviours, interactions and social contexts without the use of statistical procedures or quantification” (Fossey et al., 2002, p. 717). Thus, it can be argued that qualitative methodologies are best suited to environments that are high in complexity and require documentation of the nuances of human behaviour. Despite claims that qualitative research is unscientific, there has been an accumulation of qualitative research in rehabilitation over the last several decades. However, the ability to draw on this extensive research base in a systematic way has remained limited. Hunt (1991) claimed that “dogged commitment to pluralistic approaches [incorporating non-quantitative research] without applying methods for critical scrutiny is equally damaging as following dominant frameworks” (p. 41). Research that has passed rigorous critique will naturally command greater credibility and dependability than research that has not been
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evaluated in the same way. Indeed, the fundamental work of science is to produce critical information and refine knowledge, using the most appropriate research methods. Without methods of critical evaluation, research will be ignored, paradigms cannot be refined and alternative views cannot be advanced. Underlying this lack of inclusion of qualitative research is the common assumption that qualitative literature is inherently unsystematic. Qualitative research has frequently had to deal with criticisms that it is “anecdotal, ungeneralisable and a poor basis for making decisions” (Green & Britten, 1998, p. 230). However, qualitative research involves a complex weave of procedures, checks, re-analyse, and reviews to reach credible conclusions. Researchers have argued this point, highlighting the fact that qualitative research methods are systematic and responsive to the data in question, and the researcher must deliberately scrutinise the data according to the fundamental principles of the relevant framework (Malterud, 2001; Green & Britten, 1998). Integrating this wealth of qualitative data into a systematic body of knowledge is crucial to the process of broadening our understanding of the impact of rehabilitation. Although systematic review methods have been established for experimental trial research (i.e., RCTs), the same techniques are not appropriate in qualitative research designs. As a result of the strict EBP protocols, the knowledge-base does not incorporate the last few decades of qualitative research, despite the fact that this data mirrors the complexities of the rehabilitation experience and has considerable potential to improve practice. As reported by Devers (1999), qualitative methodologies, such as narrative accounts, interviews and focus groups and the like, are highly appropriate qualitative methodologies to
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address concerns about health service systems characterised by complexity and change processes. In this regard, qualitative research is able to address the subjective meaning and experience of individuals and systems, and the relationships between them (Fossey et al., 2002). It is perhaps ironic that the qualities of rich description and dense exploration of a topic area as found in qualitative research are the very same qualities that prevent systematic analysis and make the generalisation of findings less likely (Robinson, 1990). An underlying assumption that serves to polarise qualitative and quantitative research is the belief that these paradigms are opposing frameworks with differing philosophical assumptions (Jones, 2004). Although there is some merit in this view, pragmatist approaches have recognised the limitations and contributions of both qualitative and quantitative methods, and have advocated for mixed method studies that combine them at different phases of the research (Onwuegbuzie, 2002; Tashakkori & Teddlie, 1998). Qualitative research provides insight into the “social worlds of consumers when a point of understanding is to be reached, and when there is a need to explore broader social and organisational contexts” (Popay & Williams, 1998, p. 35). However, it has unique application when paired with quantitative methods. The intentional inclusion of both qualitative and quantitative research is essential in order to address uncertainties in many areas of health care and rehabilitation (Dixon-Woods, Fitzpatrick & Roberts, 2001). For instance, qualitative research can assist with improving the accuracy and relevance of quantitative findings, identifying and refining the questions under review, identifying appropriate variables to be measured in quantitative research, highlighting the shortfalls in the methods used in
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quantitative studies, explaining unexpected results from quantitative work and assisting in its interpretation and in making recommendations to practitioners (Dixon-Woods et al., 2001; Nutley, Walter & Davies, 2003; Popay & Williams, 1998). The demarcation between quantitative and qualitative research is becoming increasingly blurred, with each approach informing the practices of the other (Devers, 1999; Mays & Pope, 2000). The Science-Practice Gap Even when both quantitative and qualitative research are considered as evidence, there is an ongoing discrepancy between ‘what is known’ (i.e., evidence) and ‘what is done’ (i.e., practice). Poor translation of research into practice has diminished the value of EBP and is symptomatic of the lack of a reciprocal relationship between researchers and practitioners. Many studies have documented the evidence-practice gap, that is, the lag between recommended research guidelines and clinical practice implementation of these guidelines (Grol, 2001; Schuster, McGlynn & Brook, 1998). In a review of the implementation of EBP, Grimshaw and Eccles (2004) reported that up to 40 percent of clients received care that did not comply with current scientific evidence. Based on these findings, and despite the demand for researchers to actively promote the transfer of their research findings into practice, clinicians appear to have underutilised the rehabilitation research output to inform their practice. Researchers also do not appear to disseminate their findings effectively. For instance, in a review of research application by Graham and colleagues (2003), less than half (47%) of researchers disseminated their findings to consumers. It could be reasonable to conclude that even when clinicians do have access to research, practitioners often
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experience difficulty in coherently summarising the complex and conflicting research output. They rarely have the time to comprehend the central concepts contained in lengthy and sophisticated articles (Whitstock, 2003), and practitioners are rarely trained in the critical appraisal of research, making the transfer of knowledge particularly difficult. In early research, Argyris and Schon (1974) referred to espoused theory and theory-in-use (Wilkinson, 1999) and noted the value of implicit clinical knowledge as evidence. Schon (1983) also distinguished between two types of knowledge, namely technical knowledge (i.e., empirical science) and tacit knowledge (i.e., linked to experience and expertise). In the uptake of EBP, clinical or tacit knowledge has largely been usurped by the technical knowledge approach of the strict evidence-based paradigm. Clinical knowledge has been dismissed as individual judgements that only serve to bias treatments and increase variation in clinical outcome. Although the purpose of EBP is to develop guidelines to assist practitioners in their application of ‘best evidence’, these guidelines are often removed from the clinical realities experienced by practitioners. EBP has rarely been informed by clinical knowledge (Ter Meulen & Dickenson, 2002). Indeed, the scientific paradigm can invoke a paternalistic view that evidence is generated by objective researchers automatically in the best interest of the client and is plausible for the clinician (Ter Meulen & Dickenson, 2002). Clinical judgement is excluded from EBP particularly in the absence of methods that incorporate and validate experiential knowledge. It is typically considered inadequate to base practice solely on clinical judgement.
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The exclusion of clinical data was never the intention of EBP. Sackett and his colleagues (1996) described, “without clinical expertise, practice risks becoming tyrannized by evidence, but without best available evidence, practice risks becoming rapidly out of date” (p. 71). Rather than being perceived as the “black box that determines decisions”, EBP should be considered as “an open, reflective process which involves civic society ... only in this way can [EBP] contribute to the democratization of … health policy” (Ter Meulen & Dickenson, 2002, p. 240). Establishing a balance between informed clinical judgement and research evidence should be a key consideration in rehabilitation, and achieving this balance remains the challenge for EBP in general. It is insufficient to merely encourage the translation of evidence into practice. It is also necessary to ensure the relevance and utility of the evidence to practitioners and consumers (Whitstock, 2003). Recognising the practitioner as an integral part of the research process is a necessary step in translating research into practice. As stated by Whitstock (2003), “evidence is not implemented in a simple linear way, but in an evolving process influenced by the [practitioners’] personal and professional experience and by their knowledge of and relationship with their [clients]” (p. 218). The inclusion of practitioner knowledge and practice early in the research process, rather than as a token consideration at the conclusion of the research, is crucial in ensuring the relevance of research and therefore redressing the evidence practice gap. What kind of knowledge can rehabilitation practitioners offer evidencebased practice? Clinical knowledge can be the result of reflective practice informed by organised thought processes, such as self-awareness, problem
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identification, examination and analysis, tentative interpretation and synthesis, and plan of action (Atkins & Murphy, 1993; Jones, 1995; Van Manen, 1995). Engaging practitioners in these formal thought processes and experiential analyses overcomes the criticisms that practice is unscientific and intuitive (Welsh, & Lyons, 2001). In a similar vein, Wilkinson (1999) suggested that reflective practice can redress the science-practice gap through active reflection as opposed to recollection. Active reflection denotes the combination of technical knowledge and tacit knowledge to address each situation, in addition to critical analysis of one’s practice philosophy. Indeed, reflective practice permits the ownership of knowledge and deepens the learning experience through the development of a questioning attitude (Boud, 2001). However, EBP does not typically allow for the expression of clinical knowledge and nor does it sanction clinical debate. As a result, EBP tends to subvert this important process of knowledge ownership and therefore inhibit meaningful application of evidence to practice. Many current rehabilitation practitioners are unlikely to use evidence in their practice if it continues to be produced in its current form and remains removed from real clinical experience. Although a synthesis of quantitative research can provide an evidence-base for clinical decision making, the findings from these reviews alone “do not make decisions nor replace the need for compassionate practitioner judgement” (Cook, Mulrow & Haynes., 1997, p. 378). The inclusion of experts (i.e., individuals who are not part of the research team) in the research process can provide an objective viewpoint based on experience, thereby validating descriptive information contained in the findings. Experts can
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also provoke new ways of understanding. As noted by Sandelowski (1998), including experts in the research process is necessary “to be accountable to diverse communities to whom researchers wish to appeal” (p. 471). Experts, by definition, are individuals with special knowledge about a topic area (Morris, 1977). Practitioner experts are experts who function within a clinical environment and can be engaged in research for the purpose of sharing clinical expertise or practical knowledge (Sandelowski, 1998). In addition to assisting with the validation of findings, the inclusion of practitioner judgement in the research process promotes the original intent of EBP (Sackett et al., 1996). In recent years, rehabilitation researchers have demanded the inclusion of stakeholders perceptions in research to redress the dominance of academic frameworks and to ensure more meaningful conclusions are made from research (Krause et al., 2001). Similarly, medical research has called for the “reality of clinical practice to inform clinical research and for the development of research methods that will allow this to happen” (Kesselring, 2001, p. 215). Meaningful and applicable knowledge can only arise by grounding research design, performance and interpretation in a thorough understanding of the relevant clinical knowledge and practice environment (Whitstock, 2003). Researchers have extended this argument by suggesting that clinicians ought to be involved as producers of the knowledge base, rather than only as end-stage consumers (Whitstock, 2003). To this end, the views of clinicians must be included at an early stage in the evidence development process.
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Summary The philosophical influences that underlie the rise of EBP are important in understanding how notions of evidence have developed in rehabilitation research. Specifically, EBP has been influenced by the dominant positivist scientific paradigm and has not responded to the call for post-positivist or pluralistic frameworks of research. It is important to challenge dominant frameworks in order to advance knowledge to a new level and to find solutions to complex problems that cannot be addressed through reductionism and quantification. Failure to respect and integrate all types of research evidence is problematic if one intends to develop knowledge. An approach that does not address the complexity of evidence can lead to partial and unsophisticated findings that fail to translate into practice. The inclusion of clinical evidence is also necessary to facilitate the development of knowledge and the translation of that knowledge into practice. Unlike medicine, rehabilitation is a relatively new discipline. It is dependent on a changing and complex social context and must respond to the complicated and diverse needs of clients and their environments. Although is has been concluded that rehabilitation may be an effective intervention (Kenyon, 2003), its technology and methodology remain exploratory and undefined. As such, there is insufficient consistency in practice to enable the widespread application of RCTs (Level Two evidence). As a corollary, there are insufficient RCTs to support reliable and meaningful meta-syntheses (Level One evidence). Consequently, rehabilitation remains a discipline without an evidence-base.
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However, as argued in this thesis, the developmental stage and nature of rehabilitation necessitates a different kind of evidence, namely evidence that can refine practice and focus energy onto critical factors that can facilitate successful return-to-work outcomes. The evidence-base must accommodate complex configurations and permutations, but must be accessible to practitioners. Indeed, research evidence cannot be separated from its social context (Nutley et al., 2003). Most importantly, the evidence-base must provide a new level of knowledge that can promote the ongoing development of rehabilitation strategies which, over time, may be tested in RCTs. The generation of knowledge and the collation of evidence is an ongoing cyclical process that should be dependent more on the systematic process of collecting data rather than on the type data or the research design. It has been argued in this chapter that a consequence of the scientific paradigm that underlies EBP has been the over-interpretation and rigid application of the hierarchy of research quality. As a result, valuable evidence has been overlooked when what is really needed is a systematic method for collecting and collating this data. This thesis will develop and demonstrate a process for creating an expanded evidence-base in rehabilitation using low back injury as a worked example. Specifically, the thesis will demonstrate a process for broadening the research evidence beyond the dominant scientific paradigm. Through the application of an innovative multi-stage methodology, it will identify the predictors of return-to-work outcome and develop a conceptual framework to underpin future interventions.
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CHAPTER 2 THE EVIDENCE IN REHABILITATION FOLLOWING LOW BACK INJURY
A complex injury that is often associated with prolonged or multiple work absences and high compensation costs is low back injury (LBI). LBI remains a major medical and social problem that is associated with ongoing health problems, work absenteeism and high social and economic costs (Staal et al., 2003). The majority of individuals who experience LBI will recover within one to two weeks (Trunchon & Fillion, 2000), irrespective of the type of treatment received (Waddell, 1987). However, a smaller percentage (i.e., ten to twenty percent) will experience significant problems over the next three to six months (Haigh & Clarke, 1999; Hashemi, Webster, Clancy & Volinn, 1997). Despite improvements in injury rehabilitation funding and legislation, the cost of LBI continues to increase presumably due to the sub-population who experience chronic problems and eventually become work-disabled (Dunstan & Covic, 2006). It is this sub-group that has become the focus of significant and costly rehabilitation efforts. In an attempt to facilitate work participation and decrease the disruption of LBI to work, rehabilitation practitioners have been encouraged to base their interventions on evidence (Dunstan & Covic, 2006). However, evidence is mainly available about physical rehabilitation programs, which has prompted the prolific development of interventions such as back schools, physical therapy programs and multi-disciplinary programs primarily aimed at restoring functional capacity
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and reducing pain (Aure, Nilsen & Vasseljen, 2003; Dionne et al., 1997). Despite these interventions, prolonged work absences and limited work participation persist for this population (Butler, Baldwin & Johnson, 2006; Marras, 2000). In an efforts to better understand LBI and return-to-work outcomes, numerous non-biological (i.e., non-physical) factors have been examined, such as psycho-social and workplace-related factors (Crook, Milner, Schultz & Stringer, 2002; Dasinger, Krause, Thompson, Brand, & Rudolph., 2001; Deyo & Deil, 1988; Disler & Pallant, 2001; Feuerstein, Menz, Zastowny & Barron, 1994; Franche & Krause, 2002; Westmorland & Williams, 2002). However, there are few RCTs that evaluate interventions based on these factors. Further, the empirical (i.e., quantitative) evidence to support the use of these factors in intervention trials is sparse and disparate, causing practitioners to seek additional sources of evidence (i.e., non-quantitative) to understand the complexity of outcome following LBI. These additional sources of evidence have the potential to provide a more detailed understanding of the factors relating to outcome. However, in the absence of a unified and coherent evidence-base that explains the factors relating to outcome, it will be difficult to progress appropriate intervention research. This chapter will explore the nature of LBI and its impact on return-towork. The existing research in this area will be examined in relation to the determinants of outcome, and the issues that must be addressed to produce a sound evidence-base will be explored.
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The Nature of Low Back Injury An injury is a disruption to body tissue in one or multiple body parts, resulting in pain and reduced mobility (Kumar, 2001). Occupational LBI is defined as any non-specific soft tissue injury to the muscles, tendons or nerves of the lower back (i.e., lumbar region), either caused or aggravated by work (Workers Health and Safety Centre, 2003). LBI can be caused by a single event or it can build up over time as a result of repeated trauma to the muscles, tendons and nerves of the lumbar spine (i.e., low back), causing chronic pain and debilitation. (Workers Health and Safety Centre, 2003). The most common symptoms of LBI include intermittent or constant pain, and loss of mobility and flexibility, which impacts on daily activities both at home and work. Activities that include fixed or constrained body positions for extended periods of time, repetition of movements, and a pace that does not allow for sufficient recovery between movements often results in LBI (Workers Health and Safety Centre, 2003; Kumar, 2001). Research has suggested that several predisposing factors, combined with physical features of the workplace, contribute to the onset of the injury. For instance, workers with musculoskeletal injury are likely to be females who smoke, have undertaken post-secondary education, have high job-person mismatch, competing job demands and poor ergonomic workspace design (Dempsey, Burdorf, & Webster, 1997; Frank et al., 1996; Polyani et al., 1997). Although some information is available to guide prevention activities, little conclusive evidence is available about the factors that could form the focus of rehabilitation interventions.
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Consequences of Low Back Injury Although the incidence of LBI has been reported as being stable in recent years (Hazard, Reid & Clark, 2000), there is an increasing incidence of chronic disability status associated with this injury (Butler et al., 2006; Molloy et al., 1999). Researchers have argued that the nature of work-related musculoskeletal injury is such that symptoms (i.e., pain) and functional deficits (i.e., any limitations to physical function) are likely to persist long after the injury has repaired (Pransky et al., 2000), and even after the individual has returned to work (Pengel, Herbert, Maher & Refshauge, 2003). Recurrences are frequent following musculoskeletal injury and the residual effects of this injury over time have been well documented (Butler et al., 2006). Unfortunately, reports of high initial return-to-work rates following LBI have failed to capture the chronic and complex nature of this condition. In one study of workers with musculoskeletal injury, it was found that approximately 30 per cent of the sample had not returned to work six months after injury, with half of this group having already been assigned a status of permanent disability (Molloy et al., 1999). Similarly, in another study of injured workers, 75 percent still reported experiencing pain up to 12 months after returning to work, and 20 percent presented with severe disability up to 12 months following return to work (Haigh & Clarke, 1999). It has also been estimated that for every 500 000 workers per year who sustain work related injuries, half of these remain off work despite being physically capable of returning to the workplace (Wiegmann & Berven, 1998). These finding highlight the importance of understanding the factors that predict chronic difficulties. The implications of LBI and its chronic consequences are
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costly. For instance, research conducted by Proctor, Mayer, Gatchel and McGeary (2004) indicated that approximately 25 percent of people with ongoing workrelated musculoskeletal disorder, including back injury, continued to require health-care services after completing their treatment. This population registered an average relapse rate of six to seven weeks, with most requiring further treatment at this time. Individuals with LBI who have returned to work have been found to be more likely to use a disproportionately high amount of resources, including sickness benefits, legal costs, disability services and hospitalisation (Haigh & Clarke, 1999). In addition to the deleterious consequences of LBI for return-to-work, its individual, organisational and socio-economic consequences can be significant. These consequences have been well documented. Individual Consequences Work offers a sense of fulfilment and purpose that may be lost during the recovery period following an accident or injury (Smith, 1992). Failure to returnto-work following an injury has both immediate and long term effects for the individual. In the immediate future, the individual can face the potential recurrence of injury though repeated physical strain. In the long-term, negative consequences can include loss of future career development and the potential for a general decline in quality of life (Gilbride, Stensrud, Ehlers, Evans, & Peterson 2000; Martz, 2003). Multiple spells of unemployment can limit the likelihood of future employment and reduce social networks or opportunities for interpersonal connections (Bartley, Sacker & Clarke, 2004; Stone, Gray & Hughes, 2003).
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Economic globalisation, increased health care costs, the drive for costminimisation, the ageing population and labour force shortages (Australian Bureau of Statistics, 2004) have created international interest in job retention for individuals with disabilities (Shrey & Hursh, 1999). Workload demands and requirements for work efficiency have increased because of these ongoing global changes in the nature of work (Petterson & Arnetz, 1997), yet people with work injury are forced to compete with healthy individuals in this increasingly complex work environment. The escalating incidence of short-term contracts and casual work positions has contributed to a growth in job insecurity (Jones, Bright, Searle & Cooper, 1998; Siegrist, 1996). Inevitably, workers with limitations, such as cognitive and/or physical difficulties, find it more challenging than non-injured workers to secure employment and move from one job into another (Burkhauser & Stapleton, 2003). Due to pressures created by the increasingly casual and flexible work arrangements, individuals returning to work following injury may experience significant uncertainty about future work, level of income, and work schedules (Murphy, 2004). Other concerns will include the capacity to manage increased workload, the effort associated with searching for work, and the process of adapting to new work locations, tasks, co-workers and supervisors (Murphy O’Neill & Kendall, 2004). At re-entry to the workplace after injury, workers may have to accept job roles that are not necessarily commensurate with their current skill level. Employees may also experience role overload, often having to respond to the demands of new tasks, new supervisors and when too many tasks are assigned in a given time period or when new job duties go beyond employees’
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current knowledge, skills and abilities (Jimmieson, Terry & Callan, 2004). Although these difficulties confront any new worker, they are likely to be more profound for injured workers who are trying to re-establish themselves at the work place. Organisational Consequences The organisational consequences of a failure to return to work following LBI are reported extensively in the literature. Employee withdrawal behaviours following work-related injury (i.e., lateness, presenteeism, absenteeism, turnover and job dissatisfaction) have been well recognised (Beehr & Gupta, 1978; Dasinger et al., 2001; Krause et al., 2001. For instance, a large proportion of injured individuals who make a claim for compensation following work injury do not return to work, but elect to retire, retrain, or change jobs (Infante-Rivard, 1997). Workers diagnosed with LBI tend to require ongoing health-care services, therefore contributing to lost productivity and protracted disability payments (Proctor et al., 2004). For instance, it has been estimated that 52 million working days are lost each year in the United Kingdom due to back pain associated with injury (Tousignant, Rossignol,Goutlet, & Dassa, 2000). In the United States of America, there were a total of 1.2 million injuries and illnesses requiring days away from work in 2005. The median duration of leave was 7 days per injury. However, 25% of these injuries resulted in more than 30 days absent. The cost of this impact is substantial (Bureau of Labor Statistics, 2005). In Australia, up to sixty-five percent of all workplace injuries are back injuries (Australian Bureau of Statistics, 2001) and the average workers compensation cost for this type of injury is twice the average cost for all other injury claims combined (Johanning, 2000).
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The average cost of claims increased by 31% between 2000 and 2002, partially due to increased duration of claims, particularly those associated with LBI and other chronic conditions (Q-Comp Annual Report 2001/2002). Approximately 44% of these claims resulted in significant time lost from work (Q-Comp Annual Report 2001/2002). Thus, LBI can be regarded as a major factor in the increasing cost of insurance premiums for organisations as well as lost productivity. Socio-economic Consequences Injuries are recognised as a major factor in the socio-economic cost of health care for non-elderly adults (Baldwin et al., 1996). Generally, the most costly injuries are those sustained at work, given that the costs of workers’ compensation are added to the costs of medical treatment. Although the direct socio-economic costs of work injury are substantial (i.e., benefit payments, legal and medical costs), the indirect costs that emerge from prolonged disability have considerable financial impact in developed economies (Keller, 2001). Indirect expenses associated with failure to return-to-work include productivity losses/absenteeism, secondary injury, employee substitution expenses, termination payments, re-training costs, and lost revenue in taxable income (Kaiser, Mattsson, Marklund & Wimo, 2001; Krause et al., 2001). Internationally, the Bureau of Labor Statistics reported a total of nearly 1.9 million injures and illnesses in private industry in a single year, resulting in $418 billion in direct costs and $831 billion in indirect costs (Proctor, Mayer, Gatchel, & McGeary, 2004). However, these figures may underestimate the actual cost of workplace injury because many injuries are under-reported or reported late (i.e., some months from the injury event occurring) (Murphy, 2003). Furthermore, the
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costs of injury to families through the loss of employment, impeded work prospects, a decline in the general quality of life and reliance on income benefits must also be considered (Foley, Gale & Gavenlock, 1995; Purse, 1998).
The Current Evidence-Base in Low Back Injury Return-to-work following an injury is a primary outcome indicator for rehabilitation services (Krause, Dasinger, Deegan, Rudolf & Brand, 2000), and a central motivation for the delivery of rehabilitation interventions. Rehabilitation programs aim to encourage an early return to the workplace to avoid the costly consequences outlined in the previous section (MacEachen, Clarke, Franche & Irvin, 2005). In Australia, legislative requirements demand that rehabilitation is offered by the employer to the injured worker as soon as possible following injury (QComp 2001/2002). In order to minimise absence from work caused by LBI, and facilitate a timely return to the workplace, rehabilitation practitioners have been encouraged to base their practice on empirically supported interventions in accordance with EBP principles (Dunstan & Covic, 2006). However, in the area of LBI, the majority of empirical evidence derives from the medical tradition, and therefore, focuses on functional programs and physical restoration (i.e., back school, intensive physical therapy). Functional rehabilitation interventions are typically aimed at enhancing the individuals’ understanding, knowledge and awareness of physical symptomatology associated with the injury, and developing management strategies. They usually constitute ergonomic, non-invasive, non-surgical initiatives. For instance, programs, such as back schools, involve a combination of
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exercise, functional restoration and training in lifting techniques, and are usually conducted by an occupational physiotherapist and physician. Outcomes from functional rehabilitation interventions are typically measured using objective data sources, such as motor function recovery, arm strength, walking/lifting capacity, and muscle fatigue (Kool, Desch & DeBie, 2002). A systematic review of back schools conducted by Elders, van der Beek and Burdorf (2000) reported that back school interventions were a more effective method of returning the injured worker to work compared to other interventions, such as incremental exercise regimes, conventional physiotherapy. In their review, seven of the eight studies showed a significant effect for back schools, whereby a combined intervention of exercise, education and functional conditioning resulted in improved return-to-work. Other reviews have similarly highlighted the value of back school interventions as a rehabilitation strategy (van Tulder, Koes & Bouter, 1997). Although return-to-work has generally been found to improve following functional interventions, there is still a large degree of unexplained variance in outcome following functional back-school interventions. Indeed, Elders and colleagues (2000) reported that the reduction in lost time from work achieved by functional interventions only reached 42%, suggesting the influence of other factors on return-to-work outcomes. In a meta-analysis of ten RCTs conducted by Guzman et al., (2001), no consistent evidence was found to support the efficacy of functionally-oriented multidisciplinary programs in improving return-to-work outcome. Similarly, in an earlier meta-analysis conducted by Di Fabio (1995), back schools were efficacious in restoring functional capacity, there did not
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substantially improve vocational or disability outcomes. The failure of functional interventions to address return- to-work outcomes can also be demonstrated in the continued high rates of prolonged disability and reduced work participation following LBI (as outlined earlier in this chapter) despite the focus on functional rehabilitation for this population. The difficulties faced by workers with LBI who attempt to return-to-work remain significant, which has prompted rehabilitation practitioners to look further a field for evidence to guide their practice and improve outcomes. Indeed, it has been concluded that LBI is a complex condition that has a multi-variate biopsycho-social basis and as such, is resistant to purely clinical solutions, such as functional interventions (Feuerstein & Beattie, 1995). Thus, in addition to delivering physical restoration programs (i.e., functional interventions), rehabilitation practitioners have recognised the potential influence of non-physical factors in promoting improved return-to-work outcomes and explaining the complexity of LBI. Bio-psycho-social models have been promoted in the last decade as a way of understanding the experience of chronic LBI (Feuerstein & Beattie, 1995; Pincus, Burton, Vogel & Field, 2002; Truchon, 2001). Bio-psycho-social models articulate the interactions between biological, psychological and social factors in the cause and treatment of injury (Truchon, 2001). The biological factors generally include medical factors (e.g., diagnosis, history of back injury), psychological factors include the subjective experiences of the injured worker (e.g., perceived pain, emotional factors, stress, support) and social factors include socio-demographic variables (e.g., age, marital status, cultural background, wage
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status) (Crook et al., 2002; Marras, 2000; Schultz et al., 2004; Tate, Yassi & Cooper, 1999; Trunchon, 2001). Support for the development of a more comprehensive and multi-variate understanding of LBI can also be found at the broader level in international frameworks of illness and disability. According to the World Health Organisation (WHO) International Classification of Functioning (ICF) (2002), an injury can be considered to be a disability to the extent that it negatively impacts on the physical and psychological capacity of an individual to conduct their job, restricts their activity level and/or limits their opportunities for full participation within society and the workplace (Baldwin et al., 1996; Verbeek, 2001). In this regard, ‘disablement’ occurs when there is a combination of (a) functional impairments, (b) activity limitations and (c) participation restrictions. This bio-psycho-social approach sits comfortably with the broader conceptualisations of disability that dominate current scholarly activity in this area. For instance, Clapton and Kendall (2004) contended that disability can be socially constructed and that post-injury vocational difficulties may not always be the direct result of disease processes or health conditions. Similarly, Boorse (1975; in Bickenbach, Chatterji, Badley & Ustun., 1999) observed that although the medical component of disablement cannot be disputed, of far more consequence is the significant role played by “features of the world built and designed by people in the creation of disadvantages that people with disabilities experience” (p. 1174). Thus, it is plausible that any conceptualisation of LBI as a disability must pay attention to the influence of factors beyond the injury and the individual, such as social, systemic and organisational factors. For
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the injured worker, just as health is considered to be a state of complete physical, mental and social well being, it makes intuitive sense that any compromise to health (i.e., injury) is likely to impact on, and be influenced by, these same factors. Reviews in the area of LBI have validated the need to extend beyond a purely functional approach to rehabilitation. For instance, multi-disciplinary interventions, rather than single discipline-based interventions, have been reported to provide the optimum rehabilitation environment for change and successful return-to-work (Feuerstein et al., 1994; Shaw et al., 2001). Specifically, intensive (e.g., 4-6 weeks), multidisciplinary interventions that included a bio-psycho-social focus (e.g., cognitive behaviour therapy, psycho-physical training, relaxation and injured worker education as well as traditional physical interventions such as exercise training, hydrotherapy, massage) have been shown to be useful in improving pain, function and vocational outcome following LBI (Guzman et al., 2001; Haldorsen, Weimgoor, Bjorholt & Ursin, 1998; Loisel, 1997; .Rossignol et al., 2000). Despite this evidence, little is known about the specific nature of the psycho-social interventions that might be useful in LBI and which factors should form the focus of rehabilitation in future. Some researchers have promoted the value of interventions situated within the workplace and designed to enhance the employer-injured worker relationship, such as modified work and employer support (Franche et al., 2005; Porru, Placidi, Carta & Alessio, 2006; Westmorland & Williams, 2002). Although there is widespread recognition of the need to integrate psychological and social factors into rehabilitation, the evidence relating to the impact of these factors on
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outcomes is scarce and scattered (NHMRC, 2004). As such, conclusions remain tentative. In an attempt to develop an evidence-base about LBI rehabilitation, research must make sense of the multiple factors that can influence outcome. In one of the first attempts at a comprehensive review of the LBI literature, Krause and his colleagues (2001) identified over 100 potential predictors of return-towork outcome following LBI. Although impressive, the clinical utility of this review is limited and confusion over the relative contribution of factors in determining outcomes persists. The systematic review process provides a structured methodology through which to refine this extensive volume of evidence, as generated by Krause et al. (2001) for example, into a more manageable form (Tranfield, Denyer & Smart, 2003). Although successful returnto-work following LBI appears to be influenced by many factors, the purpose of a review is to synthesise this knowledge in a way that better clarifies the predictors that impact on return-to-work. Targeting rehabilitation interventions to these predictors of outcome can prevent unnecessary continuation of disability, and importantly, save up to $30 for each rehabilitation dollar spent (Shaw et al., 2001). Thus, determining the empirical support for these specific predictors may lead to improved and focussed treatment plans and practice standards for rehabilitation (Galski, Bruno, Zorowitz & Walker, 1993, Ownsworth & McKenna, 2004). Methodological Challenges in Low Back Injury There have been numerous systematic reviews of LBI and rehabilitation outcome. However, the ability to draw conclusions from these reviews about
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which predictors should form the focus of rehabilitation has been restricted by a three major issues, namely the focus on (a) single ‘point-in-time’ outcome studies, (b) univariate studies of single predictors and (c) variable outcome measurement in rehabilitation. Thus, when attempting to conduct a systematic review of returnto-work it is necessary to select studies that will provide longitudinal and multivariate understanding using a consistent outcome measure that is indicative of paid competitive employment outcomes. Each of these considerations is discussed further below. The Need for Longitudinal Understanding Although contributing to the overall body of knowledge, the majority of reviews that are specific to LBI have considered the efficacy of interventions at a point in time (Elders et al., 2000; Feuerstein et al., 1994; Franche et al. 2005; Ostelo et al., 2003; Pengel et al., 2003; Maher, 2000; Turner, 1996; van Tulder et al., 1997; van der Weide, Verbeek & van Tulder, 1997;). Given their focus on the efficacy of interventions, these reviews have largely included controlled trials (e.g., RCTs). However, as suggested by van der Weide et al. (1997), the more conservative the inclusion criteria (i.e., only based on RCTs), the smaller the evidence-base with which to work. Further, interventions in rehabilitation are rarely comparable and/or consistent, leading to a lack of clarity about the factors on which they focused and the mechanisms by which successful outcomes were achieved. Thus, although these reviews provide important information about the impact of particular interventions, our understanding of the prognostic significance of multiple factors over the injury course is limited.
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Researchers have argued that rehabilitation research designs should contain longitudinal methods to account for the complexity of the injury trajectory of the individual worker (Mustard & Hertzman, 2001; Sverke, Hellgren & Naswall, 2002). Health status and vocational outcome are likely to change dramatically over time, necessitating longitudinal research to gain a dynamic understanding of disability as it evolves. Although many individuals with workrelated injuries are reported to return to the workplace in some capacity over time (Blair & Spellacy, 1989), the period of time taken to return-to-work may be prolonged and additional problems may occur after their return. Thus, simply measuring first return-to-work without follow-up evaluation over time across a range of domains (i.e., work, individual, social) may be misleading given that it is unlikely that the first episode of work disability associated with an injury will be the last episode (Baldwin, Johnson & Butler, 1996). According to Krause, and colleagues (2001), the time to first return-towork following injury has limited utility and should be complimented by measures of recurrence. For instance, high return-to-work rates have been found in studies that have used only a short follow-up period or have excluded chronic cases (>3 months symptom duration). For instance, in one RCT study reviewed by Wiegmann and Berven (1998) involving 542 participants, a return-to-work rate of 79 percent was reported. However, the average number of sick days occurring during the 2-year follow-up period indicated a higher prevalence of disability than would be suggested by the initial return-to-work rate. These conclusions are consistent with the 2001 Australian Morbidity and Injury statistics, wherein the majority of people reporting a work-related injury in
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Australia also reported a long-term health condition (ABS AST Morbidity and Injury, 2003). These findings suggest that injuries often result in recurrent periods of disability, such that first return-to-work will be an unreliable indicator of outcome. Occupational injury is an evolving process, characterised by recovery stages (Frank et al., 1996; Young et al., 2005). Determining optimal time markers can represent critical opportunities for intervention, yet there remains a degree of variability among the literature regarding what constitutes chronicity. A common classification of chronicity in musculoskeletal injury includes acute, sub-acute and chronic phases. Generally, the acute phase describes any time up to three to four weeks post injury symptom onset, subacute refers to the time between four to 12 weeks post-onset, and chronic constitutes any time after twelve weeks post-onset (Frank et al., 1996; Krause et al, 2001; Selander et al., 2002). However, other researchers have reported that a determination of chronicity can be made if injury symptoms exceed three months duration (Weigmann & Berven, 1998). Cross-sectional data does not address the fact that return-to-work occurs over time and that predictors of outcome at any one point in time may not significantly predict outcome at a subsequent point in time. Some researchers have suggested that the relative importance of predictors may alter across the injury continuum (i.e., acute through to chronic injury phases). For example, objective individual and injury determinants (i.e., age, injury symptoms, medical examination) have been shown to have a considerable impact on outcomes for the acute phase of injury (Dasinger, Krause, Deegan, Brand, & Rudolph et al., 2000; Goertz, 1990). Conversely, in the chronic phase, it has been suggested that
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subjective psycho-social and workplace-related determinants increase in importance (Fransen et al., 2002; Gallagher et al., 1989). Clearly, arriving at an accepted definition of chronicity and understanding the factors that contribute to chronicity is a major challenge for rehabilitation research. Research that aims to understand the experience of return-to-work would ideally include multiple time points (incorporating early and late follow up), rather than single follow up designs, in order to track adjustment over time and determine the impact of predictive factors at each time point. Thus, it is critical to examine longitudinal research if any insight is to be gained in this regard. Longitudinal designs enable the temporal relationships to be identified and strengthen the ability to draw conclusions about the direction of relationships that emerge. To address this need, a research synthesis that incorporates outcome studies across injury phases, using longitudinal designs, is warranted. The Need for Multi-variate Understanding A systematic review must encompass the range of factors and experiences that characterise the return-to-work process and must attempt to examine how these factors interact to influence outcome. A major issue in previous research has been the tendency to focus on either the tangible and measurable predictors that are constantly reflected in rehabilitation research (i.e., injury-related factors, demographic factors) or a single sub-set of predictors (i.e., only work-related factors, only psychological factors) (Franche et al., 2005; Truchon & Fillion, 2000; Turner et al., 2000). The tendency to focus on the effect of only one or two factors is understandable, as this univariate approach has the advantage of simplicity. However, many of the predictors that have been identified in the
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literature are likely to be subsumed by other variables if subjected to a multivariate analysis. Single-factor analysis has a tendency to over-emphasise the importance of some determinants whilst overlooking others. These studies provide valuable knowledge about specific predictors, but may be misleading in the overall interpretation of outcome. Conclusions based on evidence about how single factors operate in isolation of other factors are insufficient to address the complex and interrelated rehabilitation environment, particularly as the interactions among predictors are likely to change over time. Multi-factorial research acknowledges the number of predictors that can impact on outcome and the inter-dependence of these factors in determining outcome (Novack et al., 2001). Thus, this univariate focus has limited the conclusions that can be made about how predictors influence outcome in combination. Given the complexity of LBI, rehabilitation research that is focussed on multiple factors, rather than single factors, has the potential to provide a broader understanding of return-to-work outcomes (Marnetoft, Selander, Bergroth & Ekholm, 2001). Multi-variate analyses attempt to determine significance after considering the impact of other factors or in conjunction with other factors. Given that multiple predictors of return-to-work have been identified following LBI (Krause et al., 2001), it is crucial to consider the inter-relationships between these factors. Some efforts have been made to determine the range of predictors of return-to-work outcome following LBI by conducting research reviews (i.e., prospective cohort reviews, retrospective chart reviews) (Crook et al., 2002; Hartvigsen, Lings, Leboeuf-Yde & Bakketeig, 2004; Linton, 2000; Turner,
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Franklin & Turk, 2000; Linton, 2001; Pincus et al., 2002; Shaw et al., 2001; Trunchon & Fillion, 2000). However, the conclusions of these reviews have been derived from studies that have largely focussed on the predictive impact of single domains (i.e., work domain, functional rehabilitation domain, individual preinjury domain). A recent review of the musculoskeletal injury literature conducted by Selander and colleagues (Selander, Marnetoft, Bergroth & Ekholm., 2002) suggested that it was necessary to consider the broader rehabilitation experience and the injured worker’s entire “process of disease” (p. 705) in order to establish a comprehensive understanding of the multiple determinants of outcome over time and the complexity of rehabilitation. Although some multi-variate models of return-to-work outcome following LBI have been proposed (i.e., incorporating bio-psycho-social predictors) (Crook et al., 2002; Krause & Ragland, 1994; Oleske, Andersson, 2000; Truchon, Lavender & Hahn, 2001), a detailed understanding of these predictors, and the nature of their interaction, has been lacking. Thus, a major problem faced by clinicians and researchers is the relative paucity of sound research that explores the complex social and environmental aspects of return-to-work outcome and develops a parsimonious set of predictors that can form a basis for interventions. The Need for Consistent Outcome Measurement Attempts to determine the impact of predictors on return-to-work outcome is even more challenging due to the inconsistencies in outcome measurement reported in the literature. For instance, outcome in rehabilitation following LBI can include (a) time to return-to-work and sickness absence (e.g., Carey, Garrett
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& Jackman, 2000; Coste, Delecoeuillerie, Cohen de Lara, Le Parc & Paolaggi, 1994), (b) recurrence of LBI (e.g., Abenhaim, Suissa & Rossignol, 1988;), (c) health care expenditure (e.g., Sinclair, Hogg-Johnson, Mondloh & Shields (1997) or (d) disability status (e.g., Klenerman et al., 1995). The nature of outcome measurement indicates a different focus for rehabilitation efforts, and makes detailed, comparative analysis of research findings (i.e., impact of predictors) extremely difficult. Overly inclusive definitions of return-to-work outcomes contribute to inaccuracy when determining the impact of predictors following LBI (Krause et al., 2001). In this regard, return-to-work can include one, or a combination, of the following definitions: the type of return-to-work (e.g., full or partial return to paid employment), the level of return-to-work (e.g., change in job characteristics from pre-injury levels), involvement in other productive activities (e.g., school, home duties, sheltered employment) and the nature of any support services (e.g., supported employment, modified work) (Holzberg, 2001; Kreutzer et al., 2000; Wehman et al., 1993; Wehman et al., 1999). The impact of outcome definition is clear from a recent quantitative synthesis of 26 studies relating to employment outcomes following traumatic injury (Kendall, Muenchberger & Gee, 2006). In this review, return-to-work rates were approximately 20% higher when an inclusive definition of return-to-work (i.e., any productive activity including volunteer work) was adopted than when the more conservative definition of fulltime competitive work was used. In order to determine a clear understanding of the impact of predictors on employment outcome following LBI, the outcome measure of return-to-work
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must be consistently applied. Without minimising the significance of any productive activity on quality of life, previous research has acknowledged the importance of focusing rehabilitation efforts on individuals who are gainfully employed prior to and after injury, and on improving their financial capacity in the long-term (Baldwin et al., 1996). Although non-competitive employment has considerable social benefit, it has been suggested that a true assessment of returnto-work must include only full-time or part-time employment in the competitive workforce (McMordie & Barker, 1990). Thus, targeting interventions to the predictors that influence an individual’s capacity for competitive work is likely to facilitate improved outcomes. However, the selection of predictors becomes difficult when broad definitions of return-to-work have been used as the processes associated with nonwork alternatives may be different from those associated with work-related outcomes. Thus, in the current review, return-to-work will reflect only a return to competitive employment, but will incorporate all levels of paid work (i.e., full, temporary or part- time employment, and any level of work even if not commensurate with pre-injury levels). Non-return to work, as indicated by absence from paid work, is also considered to reflect ‘return-to-work outcome’. Although time absent from work is a common predictor of employment outcome following LBI (i.e., increased time off work predicts a decreased likelihood of successful return-to-work), it has also been considered as an outcome measure in some studies (i.e., duration of absence). The overlap between predictors and outcomes is difficult to manage without further research documenting the distinction between them (Crepeau & Scherzer, 1993) or the way in which they
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are related to each other. Thus, in the current study, the predictors of work absence (i.e., sickness absence) will be identified in addition to the predictors of return to work.
Summary LBI is a complex injury, leading to prolonged recovery periods; significant individual, organisational and social costs and a multitude of factors that influence outcome. To date, rehabilitation interventions have largely focussed on restoring functional and physical capacity to enable individuals to overcome disability and return to the workplace. However, some evidence has suggested that there is a large amount of variance in outcome that remains unaccounted for after the provision of these functional programs. Both rehabilitation practitioners and researchers have recognised the increasing costs associated with prolonged disability for workers with back injury who fail to make a timely return to work. They have also acknowledged the need to consider a more comprehensive approach to understanding return-to-work following LBI. Attempts to conduct systematic reviews of the literature in this area have contributed to a broader conceptualisation of outcome. However, the evidence to support a broad-based understanding (i.e., the combined contribution of functional, psychological and workplace factors) of outcome is still lacking, and robust empirical justification of outcome predictors continues to be elusive. The lack of appropriate methodologies from which to gather evidence about the psycho-social predictors of return-to-work outcome following LBI has restricted the scope of rehabilitation interventions. Independent findings from
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rehabilitation and return-to-work research may be combined to draw some broad conceptual conclusions. However, knowledge in this area remains conflicted, disjointed and lacking in systematic exploration. The continued reliance on ad hoc research is likely to leave rehabilitation vulnerable to costly and ineffective interventions lacking in an evidence-base. To determine the factors that predict return-to-work outcome following LBI, and develop a clinically relevant framework, a comprehensive and systematic methodology must be adopted. This methodology must be capable of considering all sources of research evidence (i.e., quantitative and qualitative) in addition to the inclusion of clinical experience. Further, any review must focus on the process of developing a meaningful framework of understanding for rehabilitation in this area. The following chapters describe a multi-phase systematic process that will be followed in the current program of research in order to produce a credible and inclusive evidence-base that can guide the development of rehabilitation interventions.
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CHAPTER 3 THE CURRENT RESEARCH PROGRAM
This chapter presents an overview of the current research program and its methodology. The primary aim of this thesis is to develop a process for synthesising the extensive rehabilitation research base in a way that combines quantitative, qualitative and clinical knowledge. This process will be demonstrated in relation to the predictors of return-to-work following low back injury (LBI). Second, this thesis aims to demonstrate how a systematic approach to the synthesis of quantitative, qualitative and clinical data can provide a coherent conceptual framework from which rehabilitation interventions can be developed. Evidence is often considered in a dichotomous manner, namely as either scientific knowledge (i.e., quantitative research) or unscientific judgement (i.e., subjective experience). As a result, qualitative research and clinical experience is usually excluded from EBP discussions. However, all these sources of knowledge can be considered to be evidence, and are clearly relevant to the establishment of a meaningful evidence base. Despite the potential value of combining all these types of evidence, it is rare that knowledge is created in this way. However, in order to develop a robust knowledge base that is of practical value, there is growing recognition that it is necessary to consolidate multiple sources of evidence (Nutley et al., 2003).
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The current study will develop and apply a multi-stage method to LBI literature to produce a meaningful synthesis of knowledge. A series of three studies will be conducted. Study One will synthesise the quantitative literature in relation to the determinants of return-to-work outcome following LBI. Study Two will explore the clinical utility of these determinants to rehabilitation practice. Finally, Study Three will review the qualitative literature to provide a rich understanding of the processes by which rehabilitation impacts on outcome (see Table 1 for an overview). Following these three studies, the findings of each will be integrated to form a final synthesis of knowledge. Table 1: Overview of the Current Research Program Study Research Method
Study Focus
Rationale
Narrative
Synthesise
Determine the quantitative support for
Systematic Review
quantitative
predictors of return-to-work following
research
low back injury
Expert Panel
Determine Clinical
Determine the clinical utility of the
Consensus
Utility
predictors of return-to-work in
Study One
Study Two
rehabilitation practice Study Three Meta-ethnography
Synthesise
Provide a framework for understanding
qualitative research
the underlying processes by which rehabilitation influences return-to-work
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Undertaking a Research Synthesis The synthesis of research evidence is gaining extensive credibility in the literature as a way of making sense of large quantities of research. There are numerous advantages to conducting a review that follows systematic procedures, including (1) the ability to replicate findings and provide an explicit straightforward process for periodically updating knowledge, (2) increased transparency of research methods, (3) standards for determining the quality of research, and (4) the development of comprehensive databases of evidence to facilitate future research (Boaz, Ashby & Young, 2002). An area in rehabilitation where research evidence is overwhelming and confused is the predictors of returnto-work following LBI. This area has been the focus of much research identifying over 100 potential predictors of return-to-work, but leading to little in the way of conclusive evidence. Despite this volume of research, LBI remains a costly injury with variable return-to-work outcomes. Thus, there is a need to collate and combine the diverse literature base to develop a coherent platform for understanding rehabilitation in this area. This type of synthesis of research evidence will permit researchers and practitioners to develop a comprehensive approach to rehabilitation, clarify uncertainties in the knowledge (Dixon-Woods, Fitzpatrick & Roberts, 2001) and develop directions for future rehabilitation practice. Given the diversity of research that exists about rehabilitation (both quantitative and qualitative), the process of synthesising and building an evidence base requires multiple strategies (Dixon-woods, Agarwal, Young, Jones & Sutton, 2004), and a process in which all forms of data are considered to be potential
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sources of knowledge. The final synthesis of evidence across data sources represents the highest level of abstraction, and can be presented as a conceptual framework or a new knowledge-base (Whittemore, 2005). As suggested by Weed (2005), any synthesis should provide more than the sum of its parts in that it should demonstrate conceptual innovation, and/or explication of concepts beyond that found in the original data. Using three separate studies and a final integrative synthesis, the current thesis will conduct a multi-stage synthesis of LBI literature to develop a conceptual framework that can guide rehabilitation in the future.
Study One: A Narrative Systematic Review The systematic review is the most widely implemented method of making sense of an extensive, and confusing, literature base. The aim of this study was to conduct a systematic review that critically summarised the quantitative evidence about the topic of investigation using a structured selection process and producing a narrative description of the findings. Narrative systematic reviews differ from statistical methods of synthesis, such as meta-analysis, in that it can include a greater range of study types, but still maintain a rigorous approach. Meta-analysis typically reports effect sizes and/or aggregates statistics in an effort to increase the objectivity of the findings (Cook, Mulrow & Haynes, 1997). Thus, the inclusion of studies is limited by the need for direct comparison of statistical data (Whittemore, 2005) and the transformation of multiple statistics into a common statistic to calculate the overall impact of an intervention (Freemantle, Wood &
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Crawford, 1998). Meta analysis is primarily used to determine questions relating to effectiveness and relies on the presence of comparable statistical information. Rather than relying on statistical analysis to determine the significance of a cumulative finding, narrative systematic reviews report summary statements of empirical support, based on the consistency of findings and the quality of the studies. For instance, a ‘strong’ level of empirical support for an outcome measure generally indicates evidence from studies that are both sufficiently high in quality, and consistent in their findings. There are numerous criteria published regarding how to determine the level of evidence in narrative reviews (CEBM, 2001). The narrative research review follows a methodical process for gathering and evaluating quantitative evidence. Specifically, a systematic review involves five key steps, namely (1) identification of a the research question (population, concept of interest, time line, and so forth), (2) systematic identification and selection of the literature, (3) reviewing of the studies according to explicit, reproducible criteria (including quality assessment), (4) critical appraisal of selected studies and (5) synthesis of findings (Cook et al., 1997; Whittemore, 2005). Step 1: Identification of the Research Question Any research review must first identify the question of investigation in order to guide the subsequent search strategy and analysis. The research question then guides the selection of study designs (i.e., randomised controlled trials (RCTs), cohort studies) that are incorporated into the review. For instance, research questions pertaining to effectiveness of treatment will require the selection of RCTs and cohort studies to make appropriate conclusions. For
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research questions aimed at determining prognosis following injury and prediction of outcomes, cohort outcome studies (prospective or retrospective) are more appropriate (CEBM, 2001). Given that the focus of the current review was based upon the need to determine predictors of return-to-work outcome following LBI, the research question for the current study was, ‘What are the predictors of returnto-work outcome following LBI?. Step 2: Systematic Identification and Selection of the Literature A systematic review necessitates an exhaustive search of the published literature using pre-determined key search terms that are pertinent to the research question. Published literature is research that is generally available in electronic databases or through manual searching of journals. Non-published literature (also called grey literature) is another source of data, and is accessed through other forms of dissemination (i.e., personal communication with author, industry-based publications, website reports). Inclusion of grey literature in a systematic review is thought to reduce publication bias (i.e., the tendency for publication of significant results only). However, the use of grey literature remains controversial and is not widely accepted into systematic reviews due to its lack of stringent peer review. Kuipers and Hartley (2006) have examined methods for dealing with this type of data (e.g., industry publications, organisational reports, independent research findings and policy documents) which would be essential in areas where published data is less prolific than LBI. In the current study, in order to maximise the number of articles retrieved, a comprehensive search strategy was employed. A systematic search was conducted using electronic databases. Researchers have found that social science
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journals lack the large scale sophisticated databases characteristic of the scientific disciplines of medicine, chemistry and engineering (Boaz et al., 2002). Therefore, searching for literature in the social sciences and public health fields requires search strategies that incorporate multiple electronic databases, such as MEDline, CINAHL, JSTOR, Expanded Academic and PubMed. Specific search terms included a reference to each of three topics, namely, work (i.e., return-to-work, employment, occupation), predictors (i.e., predictor, determinant, outcome), and injury rehabilitation, (i.e., rehabilitation, musculoskeletal, low back pain, work injury, work related injury, work disability, sprain and strain). Studies were required to include in the title a combination of these topics (see Appendix A for a detailed search strategy). Literature searches may also be restricted to a particular period in time, thereby reducing the scope of the search to a more manageable size, increasing the likelihood of consistent methodological approaches and enabling the examination of the impact of changes in policy or practice around a topic area. In the current study, databases were reviewed in November, 2004, to identify studies published between January 1980 and December 2004 inclusive. This time frame matched that used by other reviews within rehabilitation, this enabling some comparison of rehabilitation approaches (Ownsworth & McKenna, 2004; Selander et al., 2002). A citation search was also performed, using the same search terms and combination rule (i.e., presence of key search terms within the restricted time period) as the electronic database search. This search strategy ensured that, as far as possible, the relevant published studies would be identified (Hawker et al., 2002). Unpublished or ‘grey’ literature, although potentially useful in quantitative
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reviews (i.e., meta-analysis), was excluded from the scope of this narrative review because of doubts relating to quality (i.e., potentially biased foundations) and extensive costs associated with its acquisition (Cook, Guyatt, Ryan, Clifton, Buckingham, Willan et al., 1993; McAuley, Pham, Tugwell & Moher, 2000). Step 3: Reviewing the Studies The systematic search yielded a total of 1381 hits. Studies were excluded if they were unrelated to musculoskeletal injury, rehabilitation or employment. Following this initial search, a total of 486 published studies were retained for the analysis. These studies were then subjected to a number of strict inclusion and exclusion criteria. Studies were included if they were specific to LBI, were multi-variate, indicated an employment outcome2 (i.e., return to paid work, or non-return to paid work as indicated by sickness absence) and contained at least, a pre-post follow-up (i.e., longitudinal study) or review of outcome over time (in the case of retrospective designs). If sufficient data was available, studies were categorised according to the timing of follow-up(s). This categorisation enabled conclusions to be drawn regarding the impact of predictors over time. Early follow-up was indicated by the fact that all measurements occurred within the first six months of the recovery trajectory. Late follow up was indicated by the fact that all measurements occurred after six months into the recovery trajectory. Studies were also categorised according to the injury phase they represented. Although the cut-
2
Some overlap between predictors and causal factors in rehabilitation research is to be expected (i.e., factors that contribute to the onset of the injury such as age, industry type, and occupation are also likely to predict changes and adjustment over time). This overlap is plausible and difficult to tease apart, in that these factors have been reported to be the same factors that inhibit a return-towork over time, and contribute to recurrence of the injury. In the current study, predictors that were reported as such will be included in the analysis, regardless of causal determinants.
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off points for injury phases vary in the literature, there is general consensus among researchers that the acute phase refers to the first four weeks from the time of injury, sub-acute refers to the period between four to eight weeks from the time of injury, and the chronic stage usually refers to the period of eight weeks or more following injury (Hartigan et al., 2002). Mixed studies included both acute and chronic populations, and/or follow-up measurements that spanned early and late follow-up intervals. The combination of these two categorisations (i.e., follow-up time and injury phase) allowed conclusions to be drawn regarding the influence of predictors over time, and across the injury trajectory. Following application of the inclusion criteria, 430 articles were excluded for the following reasons: evidence of co-morbidity (mental illness as primary diagnosis), other disability or majority or injury type non-specific to low back injury, no recent work history prior to injury and/or last episode of treatment (i.e., more than 80% of sample unemployed for more than two years), outcome related to surgical or functional outcome without examination of other predictive factors, non-English speaking, randomised controlled trials, qualitative methodology (these studies were retained for the qualitative synthesis), insufficient data reported to indicate outcome, no follow up, or duplication of results. Systematic reviews although excluded from the main analysis, were highlighted in the initial search for integration of findings in Chapter 7. The data extracted from each study included the indicator of employment outcome (i.e., return or non-return to paid work), the predictors, whether the predictor was found to be statistically significant or non-significant, publication
63
details (first author, date of publication, study design), sample size, injury phase at time of first assessment, and follow-up time point. Quality Assessment The strength of evidence that is derived from a systematic review depends on the quality of the research that is included. Thus, the determination of research quality is a critical component in any selection process. Despite some uncertainty regarding the use of quality assessments (Juni, Witchi, Bloch & Eggar, 1999), there is growing consensus that it is a necessary step. Numerous scales are available to researchers, with some being more widely implemented than others. Indeed, a review of quality assessment scales indicated that there are at least twelve scales in existence (Colle, Rannou, Revel, Fermanian, & Poiraudeau, 2002). Although some variation between these scales is evident, several fundamental quality indicators can be identified (Hartvigson et al., 2004; van Tulder et al., 1997). The Centre for Evidence-based Medicine (CEBM) (2001) quality scale was adopted, in which a total quality score out of 7 is used to classify individual studies. According to this scale, a score of six to seven is considered high quality, four to five moderate quality, and two to three low quality. Articles with a quality rating of one are excluded on the basis of poor quality given they are less likely to be a source of reliable knowledge. Quality criteria included a determination of whether or not the study was prospective in design, had fully described the sample (i.e., total sample size, gender distribution, employment history, injury history, occupation), included the number of people who refused to participate or failed to respond (non-respondents), included the total number of participants lost to
64
follow-up (attrition rate), employed appropriate multi-variate statistical analysis and adjustments to control for bias and included standardised outcome measures. Following quality assessment, 18 (32%) of the 56 studies were rated as being of high quality (including 5 very high quality papers, scoring a rating of 7), 24 (58%) were rated as being of moderate quality and 14 (7%) were rated as being of lower quality. Only one study was excluded on the basis of insufficient quality rating of 1. The average quality score was 4.64, with most articles incorporating prospective designs (n=47, 83%), detailed sample description (n=45, 80%), multivariate statistical analysis reported in detail (n=50, 89%) and controls for confounding variables within the analysis (n=46, 80%). The use of standardised test materials at all was reported less often (n=35, 62%) as were attrition (i.e., proportion of sample lost to follow-up) (n=21, 37%), and non-response rates (n=17, 30%). Quality scores for the studies are reported in Table 2. Step 4: Critical Appraisal of Selected Studies Critical narrative analysis was conducted for each of the predictors (n=38) reported in the selected articles (n=55). For each predictor, the statistically-based conclusions found in each study were compared and contrasted. Gaps in knowledge and inconsistencies were reported. Summaries were constructed for each predictor and the strength of evidence for each predictor was determined. Tables were constructed to portray patterns of quality and significance and the final level of empirical support for each predictor. Step 5: Synthesis of Findings Statistical meta-analysis was not appropriate in the current study due to the heterogeneity of the studies in terms of follow-up time, study design, outcome
65
measures and use of common statistics (van der Weide, 1997). Thus, a standardised indicator was adopted to represent the level of empirical support for each predictor (Oxford Centre for Evidence-Based Medicine, 1999). To determine the level of empirical support for a predictor, study findings were rated according to the consistency of results across studies (i.e., significant or non-significant) and the quality of the studies (i.e., high, moderate or low quality). Strong empirical support was present if findings were consistent (i.e., 50% or more studies reporting significant findings) and based on multiple (i.e., three or more) high quality studies. Moderate support was indicated by consistent findings from at least one high quality study as well as multiple (i.e., three or more) moderate quality studies. Weak empirical support was indicated by consistent findings, but an insufficient number of studies to enable a rating of moderate or strong support. A rating of inconclusive empirical support was indicated by mixed findings (i.e., less than 50% of studies reporting significant findings, regardless of quality ratings), or insufficient evidence to support statistical significance either due to the limited number of studies or quality of the studies.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
ID
Study 1st author Anema Ash Burdorf Coste Crook Cutler Dasinger Dasinger Deyo Dixon Donceel Dozios Dozios Durand Feuerstein Fransen Fredrikson Friedman Galizzi Gallagher Gatchel Gilbert Gluck Goertz Greenough Year 2004 1995 1998 1994 1998 2003 2000 2001 1988 1999 1999 1995 1996 2001 2001 2002 1987 1995 2003 1989 1995 2000 1998 1990 1993 7 4 6 6 6 4 7 4 7 2 5 6 6 5 3 4 3 3 3 5 6 2 3 3 6
1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 1 0 1 1 0 0 0 1
1 0 1 1 1 1 1 1 1 0 0 1 1 1 1 0 1 1 1 1 1 0 1 1 1
Total Prospective Sample Quality design description Score
Table 2: Quality Assessment Scores for Individual Studies (n=55)
1 0 1 0 1 0 1 0 1 1 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0
Nonresponse analysis conducted 1 0 1 0 0 0 1 0 1 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 1
Attrition rate
1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1
Multivariate statistical analysis reported 1 1 1 1 1 1 1 1 1 0 1 1 1 1 0 1 0 0 1 1 1 1 1 1 1
Controlling for outcomes
1 1 0 1 1 1 1 0 1 0 1 1 1 1 1 1 1 1 0 1 1 0 0 0 1
Standardised measures included
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ID 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
Study 1st author Grossi Hagen Haldorsen Harkapaa Hildebrandt Hunter Janssen Kool Koopman Lancourt Lehmann Linton Nordin Nordin Oleinick Oleske Peebles Pfingsten Pransky Reiso Year 1999 2000 1998 1992 1997 1998 2003 2002 2004 1992 1993 1998 1997 2002 1996 2000 2000 1997 2002 2003 6 2 5 5 5 5 7 5 7 4 4 3 6 3 3 5 4 5 6 4
1 0 1 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1
1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 0 1 1 1
Total Prospective Sample Quality design description Score 1 0 0 0 0 0 1 0 1 0 0 0 1 0 0 0 0 0 1 0
Nonresponse analysis conducted 0 0 0 0 1 1 1 1 1 0 1 0 0 0 0 0 0 0 1 0
Attrition rate
1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
Multivariate statistical analysis reported 1 1 1 1 1 1 1 0 1 1 0 0 1 1 1 1 1 1 1 1
Controlling for outcomes
1 0 1 1 0 0 1 1 1 1 0 0 1 0 0 1 1 1 0 0
Standardised measures included
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ID 46 47 48 49 50 51 52 53 54 55 56
Study 1st author Year Rossignol 1988 Sandstrom 1986 Schultz 2004 Tan 1997 Tate 1999 Tollenson 1993 van der Geizen 2000 van der Weide 1999 van Duijn 2004 Voaklander 1995 Wernecke 1993 Av. Quality Rating Total sum 4 5 6 3 4 1 7 7 5 3 5 4.64
1 1 0 1 0 0 1 1 1 0 1 45.00
1 1 1 1 1 1 1 1 1 0 1 47.00
Total Prospective Sample Quality design description Score
17.00
0 0 1 0 0 0 1 1 0 0 1
Nonresponse analysis conducted
21.00
0 1 1 0 0 0 1 1 0 1 1
Attrition rate
50.00
1 1 1 1 1 0 1 1 1 1 0
Multivariate statistical analysis reported
46.00
1 0 1 0 1 0 1 1 1 1 1
Controlling for outcomes
35.00
0 1 1 0 1 0 1 1 1 0 0
Standardised measures included
68
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Study Two: Determining Clinical Utility This study aimed to incorporate the views of rehabilitation practitioners and validate the clinical utility of predictors identified in Study One using an expert panel method of consultation and consensus. Although the value of clinical knowledge is widely espoused, systematic use of this knowledge is rarely practiced. The lack of inclusion of clinical knowledge into the evidence-base appears to be partly due to the absence of a sound methodology by which to rigorously incorporate clinical perspectives. To incorporate practitioner knowledge early in the development of the evidence-base it is necessary to engage practitioners in the review process and utilise consultation and consensus (i.e., agreement) approaches. These approaches have frequently been employed in research where the collective view of both researchers and clinicians is necessary. Given the logistical difficulty for individuals to interact in a face-to-face exchange, remote methods of consultation, such as electronic dissemination (email) of materials, provides participants with an equal opportunity to input into the research procedure (Crouch, Dale & Crow, 2002; Goodman, 1987; Linstone & Turoff, 1975). Consensus is generally indicated by the convergence of opinion among participants (Duffield, 1993; McKenna, 1994), as represented by percentages and median scores of endorsement by experts or possibly means and standard deviations (SDs) on survey ratings (discussed in a later section). To reach consensus through consultation, the current study engaged two panels of experts, both university-based educators and rehabilitation practitioners. These panels are described in detail below.
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Participants Expert Panel One: University Educators The first expert panel comprised University-based educators (Expert Group 1) all with tertiary qualifications in rehabilitation and/or disability studies, and experience of at least three years working as a practitioner in the rehabilitation field. Faculties representing the domains of rehabilitation, health, and disability studies were selected as the focus for recruitment. Following a general invitation to all researchers within these faculties at the only University offering postgraduate rehabilitation training, seven researchers agreed to participate in the research. This expert panel comprised three experts from Human Services (disability and rehabilitation), two from Psychology and two from rehabilitation Medicine. Expert Panel Two: Rehabilitation Practitioners This second expert panel represented practitioners from the rehabilitation industry. These practitioner experts were required to be employed in the field of rehabilitation for the past three years, and hold tertiary qualifications in injury management or case management. Given that the focus of this study was on clustering and classification of predictors rather than determining generalisable findings from participants, a large sample of practitioner experts was not necessary to complete the clinical review. Small sample sizes or minimum data sets are similarly applied in cluster analysis research, where the classification or taxonomy to be developed derives from the diversity and multiplicity of the data to be classified, rather than from diversity of the participants (Milligan & Cheng,
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1996). However, given the potentially small sample size, it was important that the practitioner experts were experienced and well respected in their field, able to represent the predominant views of their profession and willing to devote the time necessary for an in depth analysis of the extensive predictor list. Due to industry confidentiality requirements, there was no direct method of identifying potential participants other than disseminating information about the study and consent forms through the major accredited rehabilitation service providers (e.g., WorkCover Queensland and CRS Australia, registered private providers of vocational rehabilitation in Queensland (provided by QComp regulatory body) and self-insured companies (accredited by QComp to provide rehabilitation in Queensland). Organisations were asked to distribute information about the study to relevant practitioners (i.e., GPs, rehabilitation counsellors/coordinators, therapists). Practitioners were asked to return the consent form by mail if they wished to participate. A total of 94 organisations were invited to participate in the research. From this general invitation, 32 practitioners agreed to participate and returned the consent form. Each participant was then contacted by the researcher and the full requirements of the task (i.e., e-mail survey) were outlined. From the 32 practitioners who originally agreed to participate, only 12 of the rehabilitation practitioners became involved once the task was explained. Two participants who had agreed to participate did not respond thereafter. Two follow up occasions (one via telephone, and one via email) were conducted to garner ongoing commitment, as recommended by Sheehan and Hoy (1997), however, this did not yield any further input from these participants. It is not clear why some participants did not
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continue, as all participants recognised the research as a valuable contribution to their knowledge base at initial contact, and saliency of material is a contributing factor in high response rates (Sheehan, 2001). It was thought that the completion of a survey may have exceeded the time available, given demanding clinical workloads and competing priorities. Although the sample size was small, the actual participation rate of 37% was consistent with e-mail survey response rates reported in the literature. In a review of e-mail survey methodology by Sheehan (2001), the average response rate over a 15 year period from 1986 through to 2000 was 39%. The final rehabilitation practitioner participant group (n=12) comprised five Rehabilitation practitioners (three private physiotherapists, one private rehabilitation coordinator, one public rehabilitation counsellor), one WorkCover case manager, four rehabilitation case managers based in self-insured employers, and two GPs who engaged in rehabilitation work. Demographics of the rehabilitation practitioners are presented in Table 3.
Table 3: Demographic Variables from the Rehabilitation Practitioners (Expert Panel Two) Demographic variables Gender (males)
50 % (n=6)
Age in years (average)
43
Tertiary qualifications
9 university 2 college
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1 post-graduate Work Location (metro)
90 %
Hours worked per week
40 hours
Practice experience
6 years
Length of time with
6.5 years
current employer
Materials The list of 38 predictors generated from Study One was first disseminated as an Excel© file via e-mail to each participant of the University-based expert panel. Participants in the University Expert Panel were invited to provide a more detailed description of each predictor generated before returning the ‘updated’ Excel file using return e-mail. Through this process, single predictors were expanded into their component parts. There were predictors that comprised multiple domains, (e.g., job strain, workplace accommodations, rehabilitation intervention) and required further definition. Following this process, the original 38 predictors were expanded into a final set of 85 items (see Table 4). Experts used the narratives constructed in Chapter 4, and the original studies if necessary, to construct additional predictor items that would be included in the survey. In a clinical context, predictors are likely to be most relevant if they are important to rehabilitation practice (i.e., are thought to influence return-to-work outcomes), are amenable to change (i.e., can be modified through rehabilitation) and can be understood according to a coherent, shared and meaningful framework
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(Krause et al., 2001). Thus, for each predictor participants used a three-point rating scale to indicate its importance and modifiability (1 =highly important or highly modifiable, 2=somewhat important or somewhat modifiable, and 3=not at all important or not at all modifiable) (see Table 5). Practitioners were then asked to classify each predictor according to a seven-point nominal scale, with each value representing one of seven categories of the typology proposed by Krause et al. (2001) and group according to the domains reflected in Study One (i.e., Individual Factors: 1= Individual Worker Factors, 2=Injury Factors, 3=Medical and Vocational Rehabilitation Factors, Work related Factors: 4=Job Factors, 5=Organisational Factors, and System Factors: 6=Insurer Factors and 7=System Factors).
Table 4: Final list of predictors
Predictors identified in the quantitative literature in Study One (n=38) Individual Factors Demographic Age (at follow-up) Gender Marital status Dependents Education Cultural background Occupation
Employment history
Predictors expanded by Rehabilitation Practitioners in Study Two (n=85)
Age (at follow-up) Gender Marital status Home responsibilities Financial responsibilities Education Cultural background Blue collar occupation White collar occupation Ability to change occupations Self-employed State of the labour market Years with current employer
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Employment status
Time off work Psycho-social Social support Emotional status Coping Pain perceptions Perceived disability Expectations of RTW
Health locus of control Injury and Health General health status Smoking Nature of injury
Functional status Physical impairment Medical history Rehabilitation intervention
Workplace factors Communication with stakeholders
Job satisfaction
Pre-injury employment Employment at time of rehabilitation entry Time off work Social support Previous mental condition Coping Pain perceptions Perceived disability Motivation Commitment of the worker Expectations of return-to-work Clear goals Sense of control Understanding of condition General health status Drug and alcohol Recurrence of injury Severity of injury Location of injury Type of injury Independence Physical limitations Previous back injury Previous medical condition Medical rehabilitation Physical rehabilitation Educational rehabilitation Multidisciplinary rehabilitation Vocational rehabilitation Psychological rehabilitation Intensity of rehabilitation General practitioner and injured worker communication General practitioner and employer communication General practitioner and rehab coordinator communication Job satisfaction Liking the job
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Co-worker support Supervisor support Exposure to risk Modified work
Workplace based rehabilitation
Workload (physical) Job Strain
Travel to work
System factors Employer size Wage compensation
Union membership Litigation
Co-worker support Supervisor support Removal of risk factor Gradual return to work Modified work Reduced hours Workplace accommodation Employer responsiveness Rehabilitation in the workplace Ergonomic strategies Accessibility of the workplace General practitioner recommendations Timely monitoring of claim Early contact with employer Time to report injury Timeliness of rehabilitation Workload (physical) Job Stress Job Rewards Job Autonomy Decision making Job Demands Job Overtime Opportunities for skill acquisition Location of workplace Ability to drive Distance to travel to work Place of residence Employer size Rate of compensation Compensability Financial disincentives Social security benefit Union membership Litigation
In addition to these key questions, qualitative responses were sought regarding the influence of each predictor in rehabilitation. Specifically, participants were asked
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to provide a brief description of why each predictor was important for rehabilitation and how it influenced return-to-work.
Table 5: Key Questions Relating to Clinical Relevance of Predictors Item
Rationale
1
Indicate how important this predictor is to successful return-to-work (responses were provided on a three point rating scale ranging from “not important” to “extremely important”)
To determine clinical relevance of the predictor
2
Describe how and why this predictor influences return-to-work (participants were encouraged to provide as much information as possible)
To understand the impact of the predictor on outcome
3
Indicate the extent to which this predictor is able to be changed by intervention (responses were provided on a three point rating scale ranging from “not at all modifiable” to “extremely modifiable”)
To determine predictors responsive to change, and thereby, establish priority for rehabilitation
4
Select one of seven categories that best describes the predictor
To provide a typology of predictors for containment of description and consistency of conceptual framework.
1. Individual Worker factors: (the biological, social and demographic indicators) 2. Injury factors: (the medical and diagnostic indicators) 3. Medical Rehabilitation factors: (treatment and intervention indicators) 4. Job factors: (specific job type indicators) 5. Organisational factors: (workplace indicators)
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6. Industry or insurer based factors: (legislative and insurer indicators) 7. Social factors: (broader social indicators at the political, policy or philosophical level)
Procedure This final list of 85 predictors and the rating scales for each predictor were disseminated to the members of the Rehabilitation Practitioner Expert Panel via email in a spreadsheet format (see Appendix B). The purpose of the second expert panel was to reach consensus regarding the predictors that held the most relevance for clinical practice (i.e., most important and most modifiable). Experts rated each predictor according to the three key rating scales and responded to the open-ended question. They also entered their responses on the spreadsheet and returned it by e- mail. Responses were checked and collated. Quantitative analysis involved an examination of inter-rater agreement and rank ordering of the predictors. Qualitative analysis involved text analysis using concept formation and concept mapping procedures. Quantitative Analysis The quantitative analysis comprised three major steps. First, the degree of inter-rater agreement was calculated to determine the level of consensus among the practitioners. Inter-rater agreement was conducted using either Cohen’s Kappa or Kendall’s Tau, depending on the nature of the scale (i.e., nominal or ordinal). Each of these inter-rater agreement methods is discussed below. Second, the rank order of predictors was determined according to the relative standing of the
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ratings assigned to each predictor in terms of importance and modifiability by the collective. Third, the combined ratings across the domains of importance and modifiability were rank ordered to allow for the identification of the most and least clinically relevant predictors. Inter-rater Agreement Descriptive statistics were employed to identify the degree of agreement (i.e., inter-rater agreement) among rehabilitation practitioners regarding the importance, modifiability and categorisation of each predictor. There are two types of inter-rater agreement analysis that are typically used for consensus methods, depending on the nature of this rating scale (i.e., nominal versus ordinal data), namely Cohen’s Kappa and Kendalls Tau. Cohen’s Kappa is utilised as a chance-corrected measure of agreement between two independent raters (Davies & Fleiss, 1982) for nominal data. For the current study, the Kappa statistic was appropriately applied to the data relating to the question of classification of predictors). Given that more than two practitioners participated in the current study, a statistical variation of this procedure was necessary. The Fleiss (1971) generalised Kappa criterion measure represents a chance-corrected measure of agreement among three or more raters who independently classify topics or subjects into categories (King, 2004). This type of analysis presumes a large group of topics (i.e., predictors) and small group of expert raters (Gross, 1986) as was used in the current study. The degree of agreement is described by the ranges of Kappa values in Table 6 (Landis and Koch, 1977):
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Table 6: Kappa values for overall agreement Kappa value
Overall Agreement Level
