use of the International Classification of Functioning, Disability and Health (ICF) in health .... been predicted by assessments in a standard environment, for.
Rehabilitation Psychology 2005, Vol. 50, No. 2, 122–131
Copyright 2005 by the Educational Publishing Foundation 0090-5550/05/$12.00 DOI: 10.1037/0090-5550.50.2.122
Operationalizing the International Classification of Functioning, Disability and Health in Clinical Settings Geoffrey M. Reed, Jayne B. Lux, and Lynn F. Bufka
Christine Trask NeuroDevelopment Center
American Psychological Association
David B. Peterson
Susan Stark
Illinois Institute of Technology
Washington University School of Medicine
Travis T. Threats
John W. Jacobson
Saint Louis University
New York State Office of Mental Retardation and Developmental Disabilities
Judy A. Hawley Minnesota Chapter, American Physical Therapy Association
Functional status may be a better indicator of health care needs and outcomes than diagnosis. Appropriate use of the International Classification of Functioning, Disability and Health (ICF) in health service settings can provide a standardized way for clinicians to communicate complex clinical assessments to other professionals, administrators, and payers. The American Psychological Association is working with the World Health Organization to develop a Procedural Manual and Guide for a Standardized Application of the ICF for use by multidisciplinary health professionals. The Procedural Manual includes operational definitions of concepts, examples of each code, and assessment information relevant to each qualifier. The purpose of the Procedural Manual is to provide health professionals with the guidance necessary for reliable, valid, and clinically useful classification. This article discusses a range of issues and problems in the application of individual ICF codes in the context of health care and offers some potential solutions.
ogy: the dignity and worth of all people, inclusion of people with disabilities in society to the fullest extent possible, and the need for advocacy to provide people with disabilities the best opportunity to maximize their independent functioning (e.g., Frank & Elliott, 2000; Riggar & Maki, 2004; Scherer et al., 2004). Chronic diseases that are significantly modified by behavioral risk factors account for increasing proportions of the disease burden in developed countries (WHO, 2002), yet health care and health policy in the United States has continued to be based largely on an acute, infectious disease model focused on diagnosis. This suggests that the role of psychology—with its focus on behavior in contrast to medicine’s historical emphasis on diagnosis—is increasingly important in health care. Medical conceptualizations based on the acute infectious disease model are frequently not appropriate for the health services provided by psychologists and do not adequately capture the breadth or aims of these services. Most interventions provided by psychologists—in rehabilitation, medical, and mental health settings—are more accurately conceptualized as aimed at the improvement of functioning in the context of chronic disease or the prevention, delay, or amelioration of the severity and course of illness rather than at the elimination of an underlying disease process. Therefore, functional status is often a better indicator of service needs and treatment outcomes than diagnosis alone, and diagnosis should not be used as the basis for
As a classification system that is intended to capture the full range of human functioning, the World Health Organization’s (WHO) International Classification of Functioning, Disability and Health (ICF; WHO, 2001) is an important development for the field of psychology in general and for rehabilitation psychology in particular. The ICF is based on a biopsychosocial approach that allows users to document the impact of health conditions on human functioning from biological, individual, and societal perspectives. The concepts and assumptions underlying the ICF reflect the values espoused in the practice of rehabilitation psychol-
Geoffrey M. Reed, Jayne B. Lux, and Lynn F. Bufka, Practice Directorate, American Psychological Association, Washington, DC; Christine Trask, NeuroDevelopment Center, Providence, Rhode Island; David B. Peterson, Institute of Psychology, Illinois Institute of Technology; Susan Stark, Program in Occupational Therapy, Washington University School of Medicine; Travis T. Threats, Department of Communications Sciences and Disorders, Saint Louis University; John W. Jacobson, New York State Office of Mental Retardation and Developmental Disabilities, Albany, New York; Judy A. Hawley, Minnesota Chapter, American Physical Therapy Association, Roseville, Minnesota. John W. Jacobson is now deceased. Correspondence concerning this article should be addressed to Geoffrey M. Reed, PhD, Practice Directorate, American Psychological Association, 750 First Street, NE, Washington, DC 20002-4242. 122
SPECIAL SECTION: THE ICF AND CLINICAL SETTINGS
limiting the eligibility of psychologists to provide services aimed at improving functioning (see the discussion in Peterson, 2005). This article explores clinical implementation issues related to the ICF, providing a brief review of clinically relevant ICF concepts and the role of functional classification in comprehensive assessment. In health care settings, the ICF has the potential to provide a standardized way for clinicians to convey to other health care professionals, payers, and decision makers the complex functional issues encountered in clinical situations. However, this cannot occur without additional guidance to enable reliable, valid, and clinically useful classification by health professionals in clinical settings. This article describes the efforts of the American Psychological Association (APA) to develop the Procedural Manual and Guide for a Standardized Application of the ICF for health professionals. In attempting to operationalize the ICF for groundlevel use in clinical settings, a number of important conceptual issues have been encountered. This article reviews these issues and the solutions that have been proposed.
Clinical Relevance of ICF Concepts Conventional thinking, particularly in disability assessment and in U.S. health and reimbursement policy, has been based on the premise that by assessing impairments in body structure and function, it is possible to determine how effectively a person will function in daily life. It has been further assumed that improvements in body structure and function exhibited in treatment settings generalize to functional gains in everyday situations. Therefore, therapy has focused on these person-level issues within the treatment environment. This process reflects the medical model, with health professionals seeking to remedy impairment. For example, if a person has muscle weakness, the goal of therapy might be to increase strength and endurance. If a person has memory impairment, the goal of treatment might be to improve recall. Frequently, however, people do not achieve the leap from improvements in body function to enhanced everyday performance or are not able to improve everyday performance to the extent that might be possible on the basis of improvements in body function. In such cases, the person may require additional intervention or ongoing assistance to function as independently or adaptively as possible. In contrast, some people function with greater independence than would be predicted from their level of impairment. The Capacity and Performance qualifiers as outlined in the ICF Activities and Participation section may be best translated clinically as the levels of functioning seen in a standardized or clinic setting (Capacity) and in everyday environments (Performance). As such, these qualifier values may be useful for describing the discrepancy that clinicians often observe between functional levels achieved in structured environments and levels of Performance in real-world ¨ stu¨n, 2003). Impaircircumstances (Schneidert, Hurst, Miller, & U ment at the body level is related to functional status, but it is not strictly predictive of functional independence and performance on an everyday basis in one’s natural environment. Behavior is widely considered to be a function of the relation between the person and the environmental context within which the person performs (e.g., Lewin, 1951), yet the health system often does not function accordingly. The ICF recognizes that the functional consequences of health conditions are not different from other behaviors in this regard (Coulton, 1980; Lawton & Nahe-
123
mow, 1973; Mead, 1934). Real-world performance has sometimes been predicted by assessments in a standard environment, for example, during functional capacity examinations (Lee, Chan, & Hui-Chan, 2001) or exercise physiology work examinations (Van Der Woude, Van Croonenborg, Wolff, Dallmeijer, & Hollander, 1999). However, the transactional perspective (Altman & Rogoff, 1987; Stokols, 1987) suggests that behavior evaluated in a standard environment may not be generalizable to an individual’s typical environment. The ICF allows for the comprehensive description of functioning, recognizing human functioning as multifaceted and involving more than just the biological aspects of health. By explicitly delineating real-world performance and environmental factors, the ICF underlines the role of the environment in human functioning. Values and assumptions embraced by rehabilitation psychologists have long acknowledged the critical role of environmental assessment in effective treatment planning (e.g., Bond & Resnick, 2000; Frank & Elliott, 2000; Szymanski, 2000). The conceptual framework of the ICF complements this treatment paradigm, as the constructs of Capacity and Performance can be used to classify what a person can or might do in contrast with what they do given their present context. The ICF can further legitimate environmental factors as foci for intervention. As rehabilitation psychologists can attest, interventions that target environmental modifications (e.g., attitudes of coworkers, responses of family members, classroom design) may be more successful than those that target the individual client (Hurst, 2003; Szymanski, 2000).
Assessment Data and Classification With the ICF The ICF is not an assessment tool, in spite of the fact that it includes ratings for aspects of functional status. It neither consists of nor specifies assessment measures or protocols for use when conducting an evaluation. Rather, the ICF is a systematic and universal framework for describing the full range of human functioning that may be affected by a health condition. The scope of ICF is much broader than the areas relevant for any particular clinical use with a given individual, and it does not assist the clinician in selecting the most salient aspects of functioning to assess or the specific instruments to use in that assessment for a given individual. The guiding considerations in the development of the ICF—(a) that the terminology used to refer to human functioning be applicable to all people and not just to people with disabilities, (b) that it be expressed in everyday words that can be readily translated, and (c) that it be accessible and familiar to health care practitioners across disciplines (WHO, 2001)—may create the appearance of a straightforward characterization of functioning in terms that are superficially compatible with both population-based health survey approaches and mainstream medical formulations. However, this appearance is misleading because many of the functions classified require sophisticated professional knowledge and clinical judgment to assess reliably. For example, there is currently a good deal of discussion about the mapping of existing survey assessments to the ICF, which seems to assume that this is a simple matter of matching up items. However, there is rarely a one-to-one correspondence between survey items and ICF codes. Rather, multiple ICF codes may underlie a particular survey response. For example, one item from
124
REED ET AL.
WHO’s own survey, the WHO Disability Assessment Schedule II, asks about the degree of difficulty the respondent experiences in understanding another person who is talking on the other side of the room. Difficulty in this area is potentially related to a range of ICF codes, including but not limited to b230 Hearing Functions, b210 Seeing Functions, b1560 Auditory Perception, b140 Attention Functions, b1670 Reception of Language, b1672 Integrative Language Functions, b2304 Speech Discrimination, and d315 Communicating With—Receiving—Spoken Messages. Another item that asks about the respondent’s degree of difficulty in recognizing a familiar person from across the room could be related to b210 Seeing Functions, b1561 Visual Perception, or b144 Memory Functions. New measures currently under development are intended to correspond more closely to ICF functional domains. Although these will be useful for generating populationbased comparative data, such surveys most likely will not capture the level of expertise and fine-grained knowledge required by health systems as a basis for health assessment, treatment planning, and treatment monitoring. In health care settings, ICF coding reflects the findings of clinical assessments conducted by health professionals. That is, the ICF does not constitute the assessment but rather provides a framework for the documentation of functional status in areas that are relevant to a particular clinical issue with an individual patient. Frequently, clinical assessments yield information that is important for clinical decision making that is far more detailed than can be categorized using the ICF. For example, every test in a neuropsychological assessment battery could map onto the ICF code d163 Thinking. Moreover, a clinical assessment would generally involve several tests of different aspects of thinking, selected on the basis of a specific referral question that varies from individual to individual (e.g., traumatic brain injury, learning disability). Performance is generally variable across tests, and the specific pattern of performance often provides important information for the clinician, for example, in localizing a brain injury. For the clinician to make a rating for d163 Thinking, multiple components of thinking as reflected on these standardized tests would have to be combined on the basis of clinical expertise and clinical knowledge of the context and relative importance of the test scores. Health professionals need to think through how the professional assessments they already know and conduct may be translated into ICF codes (Kennedy, 2003). In this regard, it is an advantage that the ICF does not force the clinician to use specific assessment procedures. Rather, the ICF offers a conceptual framework that guides health professionals in organizing comprehensive assessments within their scope of practice, identifying relevant functional domains given appropriate sources of information, and documenting and communicating the results to other health professionals, administrators, and individuals responsible for au¨ stu¨n, Chatterji, Bickenbach, Kostanjsek, & thorizing treatment (U Schnieder, 2003). The ICF supports the use of assessment strategies that are closely linked to selection of treatment goals and strategies (Bick¨ stu¨n, 1999; Post, de Witte, & enbach, Chatterji, Badley, & U Schrijvers, 1999). Tracking clinical changes, exploring outcomes of treatment, and measuring performance over time requires the use of different methodologies in different contexts. Because the ICF incorporates consideration of both the clinical and everyday environment, ideal and typical functioning, with and without as-
sistance (e.g., prosthetics, assistive devices, self-managed therapeutic strategies), the system encourages utilization of a wide variety of assessment conditions and methods and, to the extent possible, involvement of significant others and observation of a person in his or her typical environments or engaging in typical activities (Schneidert et al., 2003; Simeonsson, Lollar, Hollowell, & Adams, 2000). Each of these levels of assessment offers important and unique information. Some ICF items (e.g., those related to intellectual functioning) lend themselves to coding based directly on standardized instruments. In such cases, there are generally a variety of standardized instruments that provide a valid basis for such coding. Other items may be coded on the basis of psychometric measures that do not produce standard scores (e.g., mental status) and yet others may be appropriately coded from clinical interviews (e.g., family relationships). Finally, some items may be coded from direct observation of behavior (e.g., conversational exchange). In some instances, it is necessary to use information from key informants who have knowledge of typical behavior or performance of the person outside of the clinical assessment situation (Bracken, Keith, & Walker, 1998). Where assessment outside of the clinical environment is not feasible, it may be important to use assessment methods that are as naturalistic as possible so as to suggest levels of typical performance (Norton & Hope, 2001). Applied in this way, the ICF can support health professionals in adopting a multimodal and multielement assessment strategy (Gardner, Graeber, & Cole, 1996; Haynes, Leisen, & Blaine, 1997; ¨ stu¨n et al., 2003). Many of Karoly, 1993; Schneidert et al., 2003; U the ICF codes are not isomorphic; that is, they consist of more than one type of behavior or response. Furthermore, pure measures of many functions specified by ICF are not available and in some cases are not possible. Therefore, a thorough assessment of functioning— even in a highly targeted area—will frequently require convergent validation of Performance and Capacity through multiple measures or observations, or in multiple situations, to produce reliable ICF coding and useful information for health care decision making. Health researchers have increasingly stressed that multicomponent assessment provides a valuable foundation for case formulation, regardless of whether the components entail principally psychometric (Mikail, DuBreuil, & D’Eon, 1993; Peterson, 2000) or functional measures (Baker, 2000; Brekke, Long, Nesbitt, & Sobel, 1997; Brown, Gordon, & Diller, 1984; Brown, Gordon, & Haddad, 2000; Cohen & Anthony, 1984; Mast & Lichtenberg, 2000; Peterson, 2000; Ruehlman, Lanyon, & Karoly, 1999). The ability to validate coding through multiple sources of information as the basis for a comprehensive formulation of service and treatment requirements for a patient is critically important if the ICF is to be effective in documenting treatment priorities (Barkham et al., ¨ stu¨n et al., 2001; Tarvydas, Peterson, & Michaelson, 2005; U 2003).
A Manual for Clinical Implementation of the ICF APA’s involvement in the revision of the International Classification of Impairments, Disabilities and Handicaps (ICIDH), as the ICF’s predecessor system was known, was initiated in 1995 by Russ Newman, Executive Director for Professional Practice. Psychology has long been dissatisfied with medical conceptualizations of patient problems and treatments derived from acute infectious
SPECIAL SECTION: THE ICF AND CLINICAL SETTINGS
disease models, which lead directly to an overemphasis on diagnosis as the focus of assessment and the basis for treatment planning and reimbursement. ICIDH appeared to offer the most viable possibility of a universal system to describe the functional aspects of health conditions that would more adequately conceptualize the basis for psychological services and, more broadly, could provide a more rational basis for treatment planning at the individual level and health policy at the population level. Through APA’s work on the ICIDH revision process, it became clear that although psychologists and other health professionals almost universally endorsed the value of the ICF conceptual model, the system itself did not provide sufficient guidance for implementation in health care settings. In 1999, APA began discussions with the WHO about the development of a guide for standardized application of the revised ICIDH by health professionals. From the time of the approval of the ICF by the World Health Assembly in May, 2001, APA has been leading a multidisciplinary project to develop a Procedural Manual and Guide for a Standardized Application of the ICF for health professionals intended to facilitate reliable, valid, and clinically useful classification using the ICF in health care settings. The APA and the WHO agreed that APA would focus on developing an English-language manual appropriate for use in industrialized English-speaking countries with health care systems that are substantially similar to that of the United States, whereas the WHO would have primary responsibility for non-English versions and cultural adaptations. Other participating organizations include the American Speech– Language–Hearing Association (ASHA), the American Occupational Therapy Association, the National Association of Social Workers, the American Physical Therapy Association, and the American Therapeutic Recreation Association. Members of other disciplines, notably medicine and nursing, have also been participating in the project as content experts though not as official representatives of professional societies. Discussions are underway with organizations that represent these and other health professionals. A prototype of the Procedural Manual, including an introduction and four chapters, was developed and field tested in both individual and consensus conference format field trials. A draft of the Procedural Manual is expected in late 2005, which will be extensively circulated for review, comment, and field testing. The audience for the Procedural Manual is multidisciplinary health professionals who have the training to independently assess clients and make a diagnosis or recommend a course of treatment within their scope of practice. On completion, the Procedural Manual will specify a standard approach to classification using the ICF system and will assist health care professionals in making reliable and valid classifications that are relevant to health service delivery. A parallel goal of the Procedural Manual is to increase the acceptance and use of the ICF within the health care delivery system, thereby increasing the consideration given to patient functioning in addition to diagnosis and moving the health care delivery system toward improved assessment, treatment planning, and resource allocation. It is hoped that the Procedural Manual will stimulate incorporation of the ICF in the education and training of health professionals. Finally, the Procedural Manual is intended to provide a foundation for strengthening the empirical basis of future revision efforts of the Procedural Manual and of the ICF itself over time.
125
Conceptual Issues in the Clinical Implementation of ICF As the Procedural Manual has been developed, aspects of the system have been further operationalized to clarify the use of codes and the array of clinical strategies appropriate to characterize functional status in terms of Performance or Capacity. Operationalization supports consistent usage of ICF codes, which is of particular importance in clinical service delivery so that difficulties in functioning and resulting priorities for habilitation, rehabilitation, or treatment can be reliably and validly identified and reported. The Procedural Manual development process has identified several key areas in which further clarification is required before the ICF system can be fully implemented in health services encounters. Most of these issues are related to the Activities and Participation chapters of the ICF, though they also arise to a lesser extent in the Body Functions chapters. They include (a) overlapping codes, (b) standard environment, (c) qualifiers, and (d) distinguishing between Activities and Participation. These issues and the drafting team’s proposed solutions are explained below. Although it is intended that the Procedural Manual also cover the Environmental Factors chapters of the ICF, these sections are not yet sufficiently developed to allow for consensus among the drafting team regarding conceptual issues and solutions. Therefore, issues related to the Environmental Factors chapters are not discussed here.
Overlapping Codes In the ICF system, each item is defined with a statement that “sets out the essential attributes (i.e., qualities, properties or relationships) of the concept designated by the category” (WHO, 2001, p. 21). Although many codes also provide guidance in the form of inclusions and exclusions of other codes, some codes within and across domains appear to be very similar if not redundant. For example, the definition for d350 Conversation is “starting, sustaining and ending an interchange of thoughts and ideas, carried out by means of spoken, written, sign or other forms of language, with one or more people one knows or who are strangers, in formal or casual settings” (WHO, 2001, p. 135). The definition for d355 Discussion is “starting, sustaining and ending an examination of a matter, with arguments for or against, or debate carried out by means of spoken, written, sign or other forms of language, with one or more people one knows or who are strangers, in formal or casual settings” (WHO, 2001, p. 136). Given the similarity, there is potential for coding error. For the ICF to be used easily and consistently across raters to characterize human functioning, additional explanation and operational examples have been developed for the Procedural Manual that assist the user in making distinctions accurately and consistently. From the perspective of clinical assessment, some codes can be differentiated conceptually but the distinction between them is not clinically meaningful for assessment, description, or treatment. This is particularly the case with certain codes in Body Functions (b codes) and the second qualifier (Capacity without assistance) for a corresponding code in Activities and Participation (see Peterson, 2005, for a summary of qualifiers). Examples of items that appear duplicative or impossible to distinguish include the following pairs of codes: Body Functions Code b140 Attention Functions and
126
REED ET AL.
Activities and Participation Code d160 Focusing Attention; b160 Thought Functions and d163 Thinking; and b16711 Expression of Written Language and d170 Writing. The ICF clearly intends a conceptual distinction between these pairs of codes in that one relates to whether a body part functions correctly and the other relates to whether an activity can be performed. However, these items cannot be distinguished clinically and would be assessed using the same tests or procedures. That is, expression of written language cannot be assessed except by writing. The Procedural Manual identifies those instances in which this arises and specifies that if both codes are used, the qualifier rating for the Body Functions code should be the same as the second qualifier rating (Capacity without assistance) for the corresponding Activity and Participation code. Take, for example, b1400.x Attention Functions and d160._x Focusing Attention; for both codes, x should be the same severity rating. In addition to overlap among codes within the ICF, there is also some redundancy between certain Body Functions codes and codes that appear in the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10; WHO, 1992). For example, b5450 Water Balance overlaps with E86 Volume Depletion under Metabolic Disorders in the ICD-10. As Peterson (2005) noted, although there is overlap between the sister classifications, the clear difference lies in the ICD-10’s diagnostic focus and the ICF’s focus on functioning. In cases of overlap, use of ICF codes can offer complementary clinical information by providing a rating of severity that is not conveyed with ICD-10 diagnostic codes.
Standard Environment To allow professionals to compare levels of functioning across patients, settings, and cultures, the ICF indicates that Capacity should be thought of with respect to a standard environment that neutralizes the varying impacts of different environments on the ability of the individual. The ICF describes the standard environment as one that is not a facilitating environment, that is, one without supports or assistive technology that increase the individual’s ability to perform the behavior in question. In contrast, the standard environment does not pose barriers to functioning. This definition is insufficient as a basis for consistent ratings in different clinical settings. The ICF suggests that the standard environment may be described by the codes contained in the Environmental Factors chapters. It is possible for the standard environment to be described generally through the environmental codes as it affects an individual and to provide an improved understanding of the support an individual receives during capacity testing. However, careful examination of these codes reveals that they are not sufficiently detailed to provide an adequate description of the critical elements of a standard environment. For example, in the assessment of bathing, it is necessary to define a standard environment by noting whether a tub or shower stall are available, the presence and position of grab bars, the presence of a fixed showerhead or hand held shower, and other relevant specifics. This level and type of detail cannot be communicated through the use of the Environmental Factors codes. The varied types of environments characteristic of different health care settings (e.g., acute, rehabilitation, long term, home),
different disciplines (e.g., therapists, surgeons, community health workers), and different regions of the world (e.g., open tent, technologically advanced hospital) all pose a challenge to providing an approximation of the standard environment that is meaningful and can be implemented clinically. For clinical applications, the standard environment must be defined in terms that are relevant to typical differences between clinics and everyday settings. At the same time, it is important to note that health professionals are trained to establish environments appropriate to the evaluation of an area of functioning and to approximate characteristics of assessment environments when the situation calls for greater flexibility. At the clinical level, then, the standard environment is not a complicated concept, provided that it is clear to the health care professional that what is meant is an assessment environment appropriate to the particular behavior being assessed. This would imply the need to establish the parameters of the standard environment more specifically than is currently the case within the ICF but in broad enough terms to allow for flexibility and clinical judgment. In drafting the Procedural Manual, we have found that it is often appropriate to define standard environments at the chapter level. For example, for the codes in the Learning and Applying Knowledge chapter (chapter 1) in the Activities and Participation section, the standard environment is defined as an assessment setting that is free from distracting auditory and visual stimuli, is free from extremes of temperature, is illuminated adequately, provides adequate privacy, and minimizes interruptions by others. The Procedural Manual contains a description of the standard assessment environment and how it is generally implemented in clinical practice within each chapter of the Activities and Participation section. In addition, if there are particular issues relevant to the assessment environment for individual codes within a chapter, these are described with that item. For example, the Procedural Manual provides guidance related to the assessment environment to the more detailed codes under d920 Recreation and Leisure (e.g., d9200 Play, d9201 Sports, d9203 Crafts).
Qualifiers The four qualifiers for the Activity and Participation codes are concepts that health professionals identify as clinically meaningful. In the case of the first qualifier, Performance in the current environment, clinicians routinely discuss and assess patients’ performance levels at home, work, school, or other day-to-day settings and use this information to guide treatment planning. The results of standardized assessments often correspond to the second qualifier, Capacity without assistance, given the specifically neutral manner in which such assessments are often administered. In some cases, treatment or intervention goals are developed to target an improvement in Capacity under conditions in which assistance is not provided, and in this regard, repeated ratings for the second qualifier may be important in monitoring an individual’s response to treatment over time. As for the third qualifier, Capacity with assistance, clinicians provide services with the goal of enhancing capacity through the most effective combination of individual or group therapy, assistive devices, and personal assistance. Capacity with assistance is routinely monitored, and often the goal of intervention is to increase the independence of an individual so that over time the reliance on assistive devices and personal
SPECIAL SECTION: THE ICF AND CLINICAL SETTINGS
assistants can be reduced or eliminated. Use of the fourth qualifier, Performance without assistance, may help to justify assistive devices and environmental modifications. Comparisons across qualifiers enable documentation and monitoring of in-clinic versus out-of-clinic behavior and an individual’s change in level of functioning in response to person level interventions or environmental modifications. However, a number of issues require clarification if the qualifiers are to be used consistently across raters. Such consistency is necessary for the ICF to be useful as a means of communication across the health system about the extent of an individual’s impairment, activity limitation, or participation restriction. Current environment. The first qualifier for Activities and Participation is Performance in the current environment. Health care professionals recognize that performance occurs in many “current” environments and may be quite variable across these different settings. Issues that arise when attempting to code this qualifier are whether best, worst, or typical performance should be recorded and, if different current environments are part of an individual’s life, which environment should be used for purposes of coding the first qualifier. The solution proposed in the Procedural Manual is obvious clinically but needs to be made explicit: The first qualifier should be coded in the context of the environment that is most clearly related to the presenting problem, focus of clinical attention, or reason for assessment. Generally, this is the environment in which the problem is most prominent. For example, it would be most informative to code Performance in the work setting for an individual with a speech fluency disorder that is problematic in his or her work setting but is much less noticeable at home with family members. This approach may differ from survey assessments, in which typical performance across environments may be appropriate. If an individual is in a temporary current environment that is much different from his or her usual current environment, such as a 30-day inpatient drug rehabilitation program, is this the environment that should be considered when coding the first qualifier? The Procedural Manual proposes that the inpatient environment be used when coding the first qualifier but that the limitations (e.g., stability) of the rating be noted in a narrative report. For people who live indefinitely in a setting such as a nursing home or a residential facility, as for people with severe and persistent mental disorders, Performance ratings would reflect the level of functioning seen in that current (albeit institutional) environment. Assistance. Although the first Performance qualifier requires coding that takes into consideration the amount and type of assistance usually in place for an individual, the classification system does not provide a way to document the type and amount of assistance used by the individual to achieve a Performance rating. Two individuals may have identical Performance qualifier ratings for an item, but one may use around-the-clock personal assistants, multiple pieces of adaptive equipment, and an environmental control unit in the home whereas the other may only use a cane. Although they appear to have the same Performance profiles, in fact their use of services and ongoing support (human and financial) is quite different. As the classification system is implemented for clinical purposes, it may be useful to add a simple coding system to reflect these individual differences, such as the one used during the beta draft testing phase:
0: 1: 2: 3: 9:
127
no assistance used nonpersonal assistance personal assistance both nonpersonal and personal assistance level of assistance unknown.
Although this approach does not give details, it does address the need to have basic information about assistance, relevant to both the first and third qualifiers—Capacity with assistance. It may also be useful to have a rating of the intensity of assistance provided (e.g., verbal cuing as compared with hand-over-hand manipulation). Because these recommendations involve the collection of additional data elements that are not part of the ICF system, they have not been incorporated into the Procedural Manual at this point. The second qualifier, Capacity without assistance, is used “to describe the individual’s true ability, which is not enhanced by an assistive device or personal assistance” (WHO, 2001, p. 230). The Capacity qualifier “aims to indicate the highest probable level of functioning that a person may reach in a given domain at a given moment” (WHO, 2001, p. 15). To implement this qualifier reliably for health care applications, it is necessary to define what is meant by “without assistance.” The concept of “naked person” is frequently mentioned in connection with the concept of Capacity without assistance. However, it is often not practical, nor may it be safe, to withhold all devices and assistance to conduct an assessment. Moreover, it may not be clinically informative. For example, if the intention is to assess a client’s reading abilities, it does not make sense to remove her eyeglasses. The recommended solution is to allow assistance that does not directly facilitate the item being coded. For example, in the case of bathing, a wheelchair might be permitted because it is not a device that enables bathing specifically, whereas long-handled sponges and a tub bench would not be permitted as these do directly facilitate bathing. Whatever solution is adopted, it must be realistic and safe to implement in clinical situations. If there is no guidance regarding the definition of “without assistance” and the standard environment, the ability to make comparisons across facilities and countries will be compromised. As previously described, a standardized environment is to be used when assessing an individual’s capacity (e.g., highest probable level of functioning). Although the challenges of describing this environment have been discussed, another clinical issue is the extent to which a standardized environment is the best environment to use to identify the highest probable level of functioning. The standard environment may be artificial and intimidating and may inhibit the demonstration of inherent capacity. Clinicians are aware of this problem and need to highlight it in clinical reports. In addition, when assessing Capacity without assistance, one needs to assess “the highest probable level of functioning that a person may reach in a given domain at a given moment” (WHO, 2001, p. 15) The Procedural Manual defines this as the highest probable level of sustainable functioning rather than a one-time all-out effort. The intention of Capacity without assistance is to provide some sort of baseline of the best functioning expected of an individual, given a standard, nonassistive environment. This is more relevant to the formulation of intervention goals than a rating based on an exceptionally high level of exertion. In contrast to the second qualifier, the third qualifier is used to code an individual’s capacity using the most facilitating combina-
128
REED ET AL.
tion of assistive devices and personal assistance. This qualifier is representative of one approach sometimes taken by clinicians when engaged in therapy with a client. Through what is sometimes referred to as “diagnostic therapy,” clinicians attempt the use of varied devices and amounts of clinician assistance or verbal cuing to facilitate a client’s maximal functioning in a specific area. However, for rehabilitation psychologists, physical therapists, and some other health professionals, there is a major philosophical question about the amount and type of assistance that should be provided when coding this qualifier. From a consumer empowerment perspective, the goal of a health care intervention is to provide whatever assistance is required for an individual with a health condition to participate in a particular activity. That is, if sufficient assistance were provided, a rating of “no impairment” would be obtained. The Procedural Manual takes the position that the assistance considered as part of coding this qualifier should be at a level that is routinely available in the treatment setting rather than highly unique, customized, or extremely expensive devices that provide unusual levels or types of assistance. Likewise, the level of personal assistance provided should be within limits that are reasonable to sustain. At the same time, it is important to acknowledge that to constrain assistance to that which can be provided within the health care setting in which the individuals find themselves may confound system and personal limitations and also limits the comparability of ratings across health care systems with widely different characteristics. However, not doing so poses a serious challenge to the validity of any rating. The use of environmental codes and/or descriptions of the amount, type, and limitations of assistance provided would help to address this dilemma. Where possible, the Procedural Manual provides specific guidance regarding the appropriate level and type of assistance for particular codes or sets of codes to facilitate consistency across raters. Performance without assistance. The fourth qualifier, Performance without assistance, is useful for when health professionals wish to describe the level of functioning of an individual without assistive devices or personal assistance in place. If an individual’s Performance in his or her current environment is supported by specific types and amounts of assistance, such an assessment might be conducted (provided it is safe to do so) to justify the ongoing provision of personal assistance or devices. If no assistance is available in the current environment, it is unclear how to differentiate the fourth qualifier from the first qualifier, Performance in the current environment, as both would be ratings of Performance without assistance. The Procedural Manual indicates that in this case, the fourth qualifier should be coded 9 (not applicable). In this way, situations in which no assistance is available in the current environment can be distinguished from situations in which assistance is available but is not effective in improving Performance, in which the first and fourth qualifiers could both be coded. At issue for all qualifier ratings is the identification of meaningful sources of information. Ratings of Performance in the current environment may be particularly well suited to self-reports or reports of other knowledgeable informants, although direct observation may be more reliable depending on the characteristics of the informant and the nature of the condition being assessed. When there is no direct information about Performance in the current environment, it is recommended that clinician predictions or estimates not be used as a basis for making ratings on the first
and fourth qualifiers. If clinical predictions are required in cases where direct observation is not possible (e.g., regarding return to work), then they should be made on the basis of Capacity assessments. The best source of information for ratings of Capacity is direct clinical assessment in a standard environment. However, it may be necessary in some cases to make Capacity ratings on the basis of self- or proxy report. It is recommended that the source and limitations of the information used to make ratings be noted in the narrative report. Aggregating qualifier ratings. As described in Peterson’s (2005) overview, the ICF is organized as a nested system in which detailed items at the third and fourth levels can be summarized in broader second-level items. Health professionals may be more interested in the detailed items, whereas administrators and policymakers may require reporting only at a summary level. In clinical situations, it is not uncommon to find variable Performance or Capacity across items at the more detailed level of classification, so some method may be required for aggregating these into a broader second-level code. For example, if a person can walk short distances (d4500) without difficulty and has only mild impairment in walking long distances (d4501) or on different surfaces (d4502) but has severe difficulty walking around obstacles (d4503), what rating is warranted for walking (d450)? Using the highest severity rating among the component parts may result in overemphasizing a less relevant detail in the context of relatively better functioning. Using an average of the third-level ratings may result in minimizing functional problems that have a large impact but are narrowly focused. Therefore, the Procedural Manual suggests that this type of aggregation generally requires clinical judgment. If the individual in the above example is a server in a restaurant, walking around obstacles is essential to occupational functioning. Therefore the Performance rating for the broader code should reflect the significance of the impairment in one of its component parts for the server’s functioning in that environment. Appropriate comparison standards. According to the ICF, limitations or restrictions in Capacity and Performance “are assessed against a generally accepted population standard. The standard or norm against which an individual’s capacity and performance is compared is that of an individual without a similar health condition” (WHO, 2001, p. 15). The Procedural Manual further clarifies that to the extent possible, standardized tests with population normative data are the method of choice for collecting information for coding Capacity. Population norms are more readily available for Body Functions and Structures items (e.g., d230 Hearing, b730 Muscle Tone Power) and for certain areas of Activities and Participation (e.g., parts of Learning and Applying Knowledge and Communication). The Procedural Manual provides information regarding the equivalence of Capacity ratings with standard scores, T scores, and the normal distribution. When standardized tests are not available for a particular item or cluster of items, the clinical evaluation may entail a more qualitative and individualized assessment. For these situations, the Procedural Manual provides narrative information regarding the extent of impairment, limitation, or restriction represented by each Capacity qualifier value. Caution is urged in such situations, however, regarding the implicit cultural or clinician values that may influence such ratings. For example, members of cultural minority groups may have different norms regarding d7601 Child–Parent Relationships or d9201 Sports. Moreover, there are some items in
SPECIAL SECTION: THE ICF AND CLINICAL SETTINGS
the last chapters of Activities and Participation for which the concept of Capacity ratings would seem impossible to apply (e.g., d930 Religion and Spirituality, d940 Human Rights). The Procedural Manual identifies these items and recommends that Capacity ratings not be made for them. In contrast to Capacity, the intention of the Performance qualifier is to represent the lived experience of the individual, which is explicitly subjective and individual. It is important that ongoing work focus on the development of useful measures of Performance that look beyond clinical environments. However, the use of standardized, normative objective instruments as a basis for Performance ratings may undermine the system’s ability to capture the experience of individuals in their particular context. This perspective is critical both to the philosophy that guided the development of the ICF and that of rehabilitation psychology. Therefore, the Procedural Manual suggests that Performance ratings be made on the basis of an individual’s particular life context, circumstances, and subjective experience, including changes from premorbid functioning. Self-reports, proxy reports, and direct observations may all be useful methods to gather information for coding the Performance qualifiers, but the experience of the individual should be emphasized as much as possible in making the ratings. Therefore, Performance ratings are likely to be less reliable across informants and less consistent over time than Capacity ratings. At the same time, however, the contrast between the objective data conveyed in Capacity and the subjective information of Performance can be invaluable in conveying a picture of the individual. This conceptualization of Performance begins to address the criticism of ICF that it fails to consider the subjective dimension of disability (Ueda & Okawa, 2003), though making this a more explicit and systematic focus of coding remains an important area for future efforts. Consider the example of a 35-year-old woman who is a partner in a law firm and has sustained a traumatic brain injury. Before her injury, she had high-level reading comprehension skills and was able to process large amounts of written material in a day. After her injury, she tested above population average in reading comprehension. Although she is able to comprehend complex written legal material given sufficient time, she is unable to manage her workload and ultimately loses her position. Now, consider the case of a 42-year-old man who works in a convenience store and has sustained the same injury. He is of borderline intellectual functioning and dropped out of high school but has been able to maintain employment at a convenience store. His preinjury reading comprehension was at the ninth grade level, which was sufficient for reading inventory and shipping reports— largely lists of items—as required for his job. After his injury, tests show moderate deficits in reading comprehension in comparison to population, which from history is likely not fully attributable to the injury. He does not complain of a change in this area, his reading ability continues to be sufficient for employment, and he is able to retain his job. The difference between these two cases would be conveyed in ICF codes through the Performance and Capacity qualifiers. For d166 Reading, the attorney would be assigned a rating of 3, representing a severe impairment, for Performance in the current environment but a rating of 0, or no impairment, for Capacity without assistance. The convenience store worker would be assigned a rating of 0, no impairment, for Performance in the
129
current environment but a rating of 2, moderate impairment, for Capacity without assistance. The extent to which Performance ratings reflect the subjective experience of the individual who is being coded also arises in relation to the issue of individual volition and values. Health professionals generally believe that there are circumstances under which their own or society’s perception of what is or is not a problem overrules that of their patients. For example, virtually all health professionals agree— except perhaps in cases of terminal disease involving great suffering—that their own perception of the undesirability of suicide is more important than the fact that a depressed patient sees it as a personal choice and a reasonable option. We do not agree that it is permissible for anorexic women to starve themselves, in spite of the fact that they may express no interest in increasing their nutritional intake. However, what if a teenager with cerebral palsy does not wish to participate in certain recreational activities because she is self-conscious about her clumsiness? These recreational activities would likely improve her general health and physical functioning, but she says that they are not important to her and that not engaging in them is a personal choice. Is there a Performance restriction for d9201 Sports? What happens when a rehabilitation psychologist’s assessment in the clinic indicates that a patient who is deaf and unable to use sign language has the capacity to work, though there would likely be social difficulties because of his communication problems and abrasive personality? The patient indicates that he has no desire to work and does not see this as a problem. Is there a restriction in Performance in the current environment for d845 Acquiring, Keeping and Terminating a Job? Or, would a rating of a restriction be based simply on the health professional’s value judgment that an adult should attempt to secure employment rather than rely on government assistance? Two guidelines are proposed. First, the clinician must be aware that assigning ratings for particular codes may be a value-laden endeavor. Determining that someone has a functional problem in d7101 Appreciation in Relationships reflects a judgment by the clinician regarding the client’s behavior and a set of implicit norms that may be culturally based or even unique to the clinician. Perceived problems in Interpersonal Interactions and Relationships (chapter 7) may instead reflect the clinician’s difficulty in interacting with the client. In using some of the codes in Activities and Participation, the clinician must recognize his or her personal values regarding appropriate interpersonal behavior, social roles, and the impact of personal choice on functional status, as well as societal and subcultural norms and expectations. Second, the codes that are rated for a particular individual should relate either to the health condition and/or to the referral question. For instance, if the evaluation is for determination of disability payments, assessment of work performance and capacity is warranted regardless of the client’s choice regarding work. When the clinician and client are likely to disagree on particular codes because of issues of values and personal choice, this should be noted in the narrative.
Distinguishing Between Activities and Participation Earlier drafts of the ICF included Activities and Participation as separate dimensions. These constructs have generally been difficult to distinguish in surveys (Perenboom & Chorus, 2003), and problems with interrater reliability noted during ICF field trials
REED ET AL.
130
suggested that users had difficulty differentiating these two dimensions in assigning ICF codes. The solution adopted in the final version of the ICF is a single list of items, any of which may be coded as Activity or Participation. Activity is defined as “the execution of a task or action by an individual,” and Participation is defined as “involvement in a life situation” (WHO, 2001, p. 14), but the determination of which items in the list fit within each concept is left to users. Although this approach offers greater flexibility, any advantages may be outweighed by the challenges it presents to reliable use. For clinical applications, however, what is most critical is not whether a code is denoted as Activity or Participation but whether the information conveyed by the four Activities and Participation qualifiers, in combination with the item definitions, provides acceptable coverage of the underlying constructs. Participation is largely a subjective experience, and the earlier example of the attorney and the convenience store worker provides a sense of how the Performance qualifier can be used to capture a part of it. What is likely to be important for treatment planning at an individual level and health policy at an aggregate level is the extent to which individuals can perform in everyday life and, when performance is not optimal, the identification of action steps to facilitate their functioning (e.g., individual treatment, environmental modification, or some combination). It is critical when applying the Performance qualifiers to retain the notion of societal disadvantage, as captured in the definition of Participation and as articulated in distinct items that appeared in earlier drafts of the ICF. Performance in the current environment should be seen as broad enough to include not only a person’s performance of tasks and activities but the degree to which he or she integrates into society and participates in life to its fullest. Whether it is important to achieve consensus on the distinction between Activities and Participation will become evident through ongoing use of ICF for different purposes in various health care sectors.
Conclusion On completion, the Procedural Manual will specify a standard approach to the ICF system in clinical settings that we hope will enable health care professionals to use the classification in a reliable and clinically useful manner. We wish to emphasize the three central points of feedback from health professionals across disciplines from our field trials of the prototype Procedural Manual. First, health professionals almost universally reported that functional status as conceptualized by the system and clarified by the prototype Procedural Manual is important for clinical practice and relevant to clinical assessment. Second, health professionals indicated that the ICF itself offered insufficient guidance for use of the system and that a Procedural Manual structured along the lines of the prototype would be essential for using the system. They found the general approach, overall structure, and content of the prototype to be useful. Finally, in spite of their view of the importance of functioning as conceptualized in the ICF and as operationalized in the prototype Procedural Manual, U.S. health professionals emphasized that the system would not be used without a health system requirement to do so, particularly one that is related to reimbursement. This suggests that sustained advocacy will be necessary to
persuade health care policymakers, payors, and government agencies, such as the Center for Medicare and Medicaid Services, of the potential value of the functional information that can be provided using the ICF. A major educational effort among psychologists and other health professionals will also be required. Rehabilitation psychology is well positioned to be leaders in both these efforts. We believe that the strong conceptual framework of the ICF, in combination with the development of a Procedural Manual to facilitate use of the system by health professionals, can provide a basis for significant improvement in today’s health care system. As meaningful data on human functioning become increasingly available, they will have widespread implications for health status assessment and health policy and lead to significant opportunities to shape the health agenda.
References Altman, I., & Rogoff, B. (1987). Worldviews in psychology: Trait, interactional, organismic and transactional perspectives. In D. Stokols & I. Altman (Eds.), Handbook of environmental psychology (Vol. 1, pp. 7– 40). New York: Wiley. Baker, P. A. (2000). Measurement of community participation and use of leisure by service users with intellectual disabilities: The Guernsey Community Participation and Leisure Assessment (GCPLA). Journal of Applied Research in Intellectual Disabilities, 13, 169 –185. Barkham, M., Margison, F., Leach, C., Lucock, M., Mellor-Clark, J., Evans, C., et al. (2001). Service profiling and outcomes benchmarking using the CORE—OM: Toward practice-based evidence in the psychological therapies. Journal of Consulting and Clinical Psychology, 69, 184 –196. ¨ stu¨n, T. B. (1999). Bickenbach, J. E., Chatterji, S., Badley, E. M., & U Models of disablement, universalism and the international classification of impairments, disabilities and handicaps. Social Science and Medicine, 48, 1173–1187. Bond, G. R., & Resnick, S. G. (2000). Psychiatric rehabilitation. In R. G. Frank & T. R. Elliott (Eds.), Handbook of rehabilitation psychology (pp. 235–258). Washington, DC: American Psychological Association. Bracken, B. A., Keith, L. K., & Walker, K. C. (1998). Assessment of preschool behavior and social– emotional functioning: A review of thirteen third-party instruments. Journal of Psychoeducational Assessment, 16, 153–169. Brekke, J. S., Long, J. D., Nesbitt, N., & Sobel, E. (1997). The impact of service characteristics on functional outcomes from community support programs for persons with schizophrenia: A growth curve analysis. Journal of Consulting and Clinical Psychology, 65, 464 – 475. Brown, M., Gordon, W. A., & Diller, L. (1984). Rehabilitation indicators. In A. S. Halpern & M. J. Fuhrer (Eds.), Functional assessment in rehabilitation (pp. 187–204). Baltimore: Brookes. Brown, M., Gordon, W. A., & Haddad, L. (2000). Models for predicting subjective quality of life in individuals with traumatic brain injury. Brain Injury, 14, 5–19. Cohen, B. F., & Anthony, W. (1984). Functional assessment in psychiatric rehabilitation. In A. S. Halpern & M. J. Fuhrer (Eds.), Functional assessment in rehabilitation (pp. 79 –100). Baltimore: Brookes. Coulton, C. J. (1980). Developing an instrument to measure person– environment fit. Journal of Social Service Research, 3, 159 –173. Frank, R. G., & Elliott, T. R. (2000). Rehabilitation psychology: Hope for a psychology of chronic conditions. In R. G. Frank & T. R. Elliott (Eds.), Handbook of rehabilitation psychology (pp. 3– 8). Washington, DC: American Psychological Association. Gardner, W. I., Graeber, J. L., & Cole, C. L. (1996). Behavior therapies: A multimodal diagnostic and intervention model. In J. W. Jacobson & J. A. Mulick (Eds.), Manual of diagnosis and professional practice in mental
SPECIAL SECTION: THE ICF AND CLINICAL SETTINGS retardation (pp. 355–370). Washington, DC: American Psychological Association. Haynes, S. N., Leisen, M. B., & Blaine, D. D. (1997). The design of individualized behavioral treatment programs using functional analytic clinical case models. Psychological Assessment, 9, 334 –348. Hurst, R. (2003). The international disability rights movement and the ICF. Disability and Rehabilitation, 25, 572–576. Karoly, P. (1993). Goal systems: An organizing framework for clinical assessment and treatment planning. Psychological Assessment, 5, 273–280. Kennedy, C. (2003). Functioning and disability associated with mental disorders: The evolution since ICIDH. Disability and Rehabilitation, 25, 611– 619. Lawton, M. P., & Nahemow, L. (1973). Ecology and the aging process. In C. L. Eisdorfer (Ed.), Psychology of adult development and aging (pp. 619 – 674). Washington, DC: American Psychological Association. Lee, G. K., Chan, C. C., & Hui-Chan, C. W. (2001). Work profile and functional capacity of formwork carpenters at construction sites. Disability and Rehabilitation, 23, 9 –14. Lewin, K. (1951). Field theory in social science. New York: Harper. Mast, B. T., & Lichtenberg, P. A. (2000). Assessment of functional abilities among geriatric patients: A MIMIC model of the functional independence measure. Rehabilitation Psychology, 45, 49 – 64. Mead, G. (1934). Mind, self and society. Chicago: University of Chicago. Mikail, S. F., DuBreuil, S., & D’Eon, J. L. (1993). A comparative analysis of measures used in the assessment of chronic pain patients. Psychological Assessment, 5, 117–120. Norton, P. J., & Hope, D. A. (2001). Analogue observational methods in the assessment of social functioning in adults. Psychological Assessment, 13, 59 –72. Perenboom, R. J. M., & Chorus, A. M. J. (2003). Measuring participation according to the international classification of functioning, disability and health (ICF). Disability and Rehabilitation, 25, 577–587. Peterson, D. B. (2000). Clinical problem-solving in micro-case management: Computer-assisted instruction for information gathering strategies in rehabilitation counseling. Rehabilitation Counseling Bulletin, 43(2), 84 –96. Peterson, D. B. (2005). International classification of functioning, disability and health: An introduction for rehabilitation psychologists. Rehabilitation Psychology, 50, 105–112. Post, M. W. M., de Witte, L. P., & Schrijvers, A. J. P. (1999). Quality of life and the ICIDH: Toward an integrated conceptual model for rehabilitation outcomes research. Clinical Rehabilitation, 13, 5–15. Riggar, T. F., & Maki, D. R. (Eds.). (2004). The handbook of rehabilitation counseling. New York: Springer. Ruehlman, L. S., Lanyon, R. I., & Karoly, P. (1999). Development and
131
validation of the Multidimensional Health Profile, Pt. I: Psychosocial functioning. Psychological Assessment, 11, 166 –176. Scherer, M. J., Blair, K. L., Banks, M. E., Brucker, B., Corrigan, J., & Wegener, J. H. (2004). Rehabilitation psychology. In W. E. Craighead & C. B. Nemeroff (Eds.), The concise Corsini encyclopedia of psychology and behavioral science (3rd ed., pp. 801– 802). Hoboken, NJ: Wiley. ¨ stu¨n, T. B. (2003). The role of Schneidert, M., Hurst, R., Miller, J., & U environment in the international classification of functioning, disability and health (ICF). Disability and Rehabilitation, 25, 588 –595. Simeonsson, R. J., Lollar, D., Hollowell, J., & Adams, M. (2000). Revision of the international classification of impairments, disabilities and handicaps: Developmental issues. Journal of Clinical Epidemiology, 53, 113–124. Stokols, D. (1987). Conceptual strategies of environmental psychology. In D. Stokols & I. Altman (Eds.), Handbook of environmental psychology (Vol. 1, pp. 7– 40) New York: Wiley. Szymanski, E. M. (2000). Disability and vocational behavior. In R. G. Frank & T. R. Elliott (Eds.), Handbook of rehabilitation psychology (pp. 499 –517). Washington, DC: American Psychological Association. Tarvydas, V. M., Peterson, D. B., & Michaelson, S. D. (2005). Clinical decision-making and ethical issues in case management. In F. Chan, M. Leahy, & J. W. B. Saunders (Eds.), Case management for rehabilitation health professionals (Vol. 1, 2nd ed., pp. 144 –175). Osage Beach, MO: Aspen Professional Services. Ueda, S., & Okawa, Y. (2003). The subjective dimension of functioning and disability: What is it and what is it for? Disability and Rehabilitation, 25, 596 – 601. ¨ stu¨n, T. B., Chatterji, S., Bickenbach, J., Kostanjsek, N., & Schnieder, M. U (2003). The international classification of functioning, disability and health: A new tool for understanding disability and health. Disability and Rehabilitation, 25, 565–571. Van Der Woude, L. H., Van Croonenborg, J., Wolff, I., Dallmeijer, A. J., & Hollander, A. P. (1999). Physical work capacity after 7 weeks of wheelchair training: Effect of intensity in able-bodied subjects. Medicine and Science in Sports and Exercise, 31, 331–341. World Health Organization. (1992). International statistical classification of diseases and related health problems, tenth revision (ICD-10). Geneva, Switzerland: Author. World Health Organization. (2001). International classification of functioning, disability and health (ICF). Geneva, Switzerland: Author. World Health Organization. (2002). The World Health Report 2002: Reducing risks to health, promoting healthy life. Geneva, Switzerland: Author.
Received December 29, 2004 Revision received February 3, 2005 Accepted February 3, 2005 䡲
