A systematic review of longitudinal studies of nonfatal workplace ...

EUROPEAN JOURNAL OF WORK AND ORGANIZATIONAL PSYCHOLOGY 2005, 14 (3), 291–313

A systematic review of longitudinal studies of nonfatal workplace violence Annie Hogh National Institute of Occupational Health, Copenhagen, Denmark

Eija Viitasara Karolinska Institutet, Stockholm, Sweden

Risk factors and consequences of exposure to violence at work were examined through a systematic review of longitudinal studies of workplace violence. Literature in different databases was screened and the articles were selected on the basis of a set of inclusion criteria. Sixteen studies were included into the review and they were evaluated according to a number of criteria recommended for use in systematic reviews. Of the reviewed studies, 12 met more than half of the evaluation criteria. The studies identified individual, situational, and structural risk factors of workplace violence. Five studies demonstrated that being subjected to violence at work have both acute and long-term consequences for the exposed staff and the workplace. Two studies also found symptoms of Posttraumatic Stress Disorder in victims. In view of the detrimental effects of violence, it is important that preventive measures are taken and evaluated in future longitudinal studies.

Over the past two decades workplace violence has been investigated extensively. A number of summary reviews have been carried out. Some of these were general reviews of violence at work (e.g., Bulatao & VandenBos, 1998; Cox & Leather, 1994; Flannery, 1996). Some reviews were more specific covering one occupation or risk sector, i.e., the health care sector (Beale, Fletcher, Leather, & Cox, 1998; Davis, 1991; Feldmann, Holt, & Hellard, 1997; Flannery, 2000; Fletcher, Brakel, & Cavanaugh, 2000; Harris & Rice, 1997; Hewitt & Levin, 1997). The reviews show that the risk of staff exposure to violence at work is especially high in service and human service jobs and violence is often the result of an interaction of individual, situational, and structural factors. Correspondence should be addressed to Annie Hogh, National Institute of Occupational Health, Lersø Parkalle´ 105, 2100 Copenhagen, Denmark. Email: [email protected] # 2005 Psychology Press Ltd

http://www.tandf.co.uk/journals/pp/1359432X.html

DOI: 10.1080/13594320500162059

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Individual risk factors may include demographic characteristics of the personnel, such as age, gender, education, and training, and also occupational and organizational experience (Viitasara, Sverke, & Menckel, 2003; Whittington & Wykes, 1994b). Situational risk factors refer to a collection of external conditions or circumstances in a work context. Such work-related characteristics, i.e., form of employment, work activities, working hours, work conditions, and workload, may decrease or increase exposure or risk (Viitasara, 2004). Structural factors, on the other hand, refer to the organizational features, e.g., the form of hierarchy and distribution of responsibilities, management and policies, and physical and psychosocial work environment (Viitasara & Menckel, 2002). The above mentioned reviews show that exposure to violence may have consequences for the health and well-being of the victims. Other studies have found that workplace violence may to lead to consequences, such as personal-financial loss, health-related consequences (i.e., injuries and emotional reactions), and work-related effects, and it may even affect life outside work (Viitasara, 2004). The health-related consequences of violence are often categorized into cognitive symptoms such as concentration and memory difficulties, emotional symptoms like nervousness, depressive symptoms, and fatigue, and psychosomatic symptoms such as stomach-ache, chestpain, and muscular tension (Hogh & Mikkelsen, in press). These consequences may be both acute and long-lasting (Ryan & Poster, 1989). However, most of the previously reviewed and the other studies are cross-sectional and cannot establish cause and effect relationships. Many of the previously reviewed studies are also methodologically deficient in different ways and often lack operational definitions or the definitions are not consistent from one study to another (Flannery, 1996). The purpose of the present review is therefore to examine prospective longitudinal studies for findings of risk factors and consequences of nonfatal violence and threats of violence towards staff at work. In the extreme form physical violence at work may be fatal; however this type of violence is very rare (Baron & Neuman, 1998; Baron & Richardson, 1994) and will not be included in the present review. A systematic approach was thus applied to answer the following questions: 1 What may constitute a risk factor of nonfatal physical violence and/or threats of violence towards staff in a workplace? 2 What are the consequences of nonfatal physical violence and/or threats of violence at work for staff and organization?

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METHOD Inclusion criteria and search strategy To be eligible for inclusion in this review, articles must have reported on: . . .

workplace violence or threats of violence risk factors, factors that give rise to an incident of violence or threats of violence, and/or consequences of nonfatal physical violence or threats of violence towards staff surveys that are based on longitudinal and prospective peer-reviewed studies including case-control studies

Exclusion criteria were cross-sectional studies and pilot studies. Relevant peer-reviewed studies were searched for in Medline, Psychlit/ PsychInfo, Sociological Abstracts and in reference lists up to the middle of 2004. The following keywords were used: violence, workplace, work-related violence, and work-related threats of violence, staff, longitudinal, prospective, and follow-up studies.

Criteria used for evaluation of the studies and methodological assessment The selected studies were scored by the two authors independently on the basis of a set of criteria that were adapted from criteria used when assessing the methodological quality of a published article (Greenhalg, 1997), and as recommended by The Cochrane Collaborations in the ‘Reviewers Handbook’ (Cochrane Collaboration, 2001), and by Zapf, Dormann, and Frese (1996). A number of methodological criteria are required if the purpose of a study is to disclose a causal relationship: The study should be longitudinal and prospective so that ‘‘cause’’ and ‘‘effect’’ are not measured at the same time. Control for confounders and bias, anything that erroneously influences the conclusions, is required and the reliability and validity of the study should be stated. It increases the reliability of the results if a control group is included in the study, and this may indicate whether other factors in the work environment have had an impact on the health outcomes (Zapf et al., 1996). A risk factor of violence can thus be said to exist if there is a covariation of potential risk factors of violence or threats of violence (violence) and the violence, if the potential risk factors were present before the violence and if other possible explanations can be ruled out. In relation to effect of violence, causality is present when there is an association between the violent/threatening incident and the effect, if the incident comes before the effect, and if other plausible explanations can be ruled out.

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When reviewing the articles studying risk factors and consequences of violence and threats of violence at work a number of questions, based on the methodological criteria, were asked. These criteria are listed in the Table 1. The present authors rated each criterion positive, negative, not applicable, or unknown (no direct information) based on the information provided in the articles. All disagreements between the authors were discussed. Disagreements would typically be about where to find the needed information in the articles, since information on, for instance, definitions or aim of the study, etc., were not always provided in the section, where we would expect to find it. If disagreements were not resolved the first time, the articles were reread and the findings discussed once more and consensus was reached. If information was not available in the reviewed article but was provided in another article and a reference was included, the criterion was rated positive and listed with an ‘‘a’’ in Table 2. If the study was a case-control study, the follow-up of the baseline would not be necessary if the cases and controls were followed. The criterion for follow-up response rate would thus be rated as ‘‘not applicable’’. Consideration of time period between measurements and information on dropouts is not relevant in case-control studies and these criteria were thus rated as ‘‘not applicable’’. For an evaluation of the studies all positive answers to these questions (including relevant information given in other articles) were added up and divided by the number of relevant evaluation criteria (not including the ‘not

TABLE 1 The criteria used in the evaluating process 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

Is there a baseline study? Are definitions of the phenomena clearly stated? Does the study have a clear design that corresponds to the theoretical problems/research question? Are the measurement instruments described? Are the variables measured with the same method every time? Is the time period between the measurements well considered? Is the follow-up period long enough to be able to measure late reactions? (consequences) Are the hypotheses/research questions stated and discussed? Are incident reports of risk factors evaluated by another person than the exposed staff member? Is information on dropouts provided? Have the potential correlations been tested by relevant statistical tests? Have potential cofounders/bias been considered? Is the validity of the measures described? Is the reliability of the measures described? Does the study include a control group? Is the response rate at baseline provided and over 70%? Is the response rate at follow-up provided and over 70%?

TABLE 2 Evaluation of the included studies

a. Aiken, 1984 b. Arnetz & Arnetz, 2000 c. Beale, Clarke, Cox, Leather, & Lawrence, 1999 d. Bjørkly,1999 e. Carmel & Hunter, 1989 & 1993 f. Chou, Lu, & Chang, 2001 g. Cooper & Mendonca, 1991 h. Crilly, Chaboyer, & Creedy, 2004 i. Fisher & Jacoby, 1992 j. Flannery, Stone, Rego, & Walker, 2001 k. Flannery, Stevens, Juliano, & Walker, 2000 l. Harris & Varney, 1986 m. Hogh, Borg, & Mikkelsen, 2003 n. Ryan & Poster, 1989 o. Whittington & Wykes, 1994b p. Wykes & Whittington, 1998

11

2

3

4

5

6

– + /

+ a +

+ + +

(–) + a

+ + +

(–) + /

– – – – + – –

+ + – + + – +

+ + + (–) + + +

+ + + – + a a

+ + + (–) + + +

–

+

+

a

– + + – +

+ – + + +

+ + + + +

+ + + + +

7

16

17

%2

– + +

/ + /

/ – /

40 94 100

+ – + – + + –

– – + (–) + +3 –

/ / / / – / /

/ / / / / – /

67 42 83 25 92 68 46

–

–

–

/

/

58

– – + – +

+ – – – +

+ + + + +

/ + + / +

/ + + / +

69 81 88 75 94

8

9

10

11

12

13

14

– / /

+ + +

+ + +

– + /

+ + +

– + +

– + a

– + a

/ / / / / – /

/ / / / / + /

+ + + + + + –

+ – + (–) + + +

/ / / / / + +

– – + + + + –

+ – + – + + –

– – + – + – –

+

/

/

–

+

/

+

+

+ + + + +

/ + + / +

/ + + / +

+ + + + +

+ / / + (–)

– + + / +

+ + + + +

– + – + +

15

+ = positive, – = negative, / = not applicable, () = no direct information. a: references are given to other articles, where the instruments and measurements are discussed. 1 The numbers refer to the criteria listed in Table 1; 2percentage of criteria met in the review; 3the study includes a control group at baseline, but not at follow-up.

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applicable’) and the results were included in percentages in the last column of Table 2.

RESULTS: REVIEW OF THE INCLUDED STUDIES Studies on ‘‘risk factors of violence/threats of violence at work’’ Sixteen studies met the criteria for studies on risk factors and/or consequences of violence and threats of violence mentioned above. Fifteen studies reported risk factors of violence. Five studies measured both risks of and consequences of violence. Two articles reported on the same study (one is a follow-up of the other) and they are included as one study (Table 1). All the studies were longitudinal and 10 were also case-control studies. The methodology of these studies is mainly described in this section on risk factors of violence. Psychiatric health care A study of nursing staff in a Californian Neuropsychiatric Hospital consisted of three parts (Ryan & Poster, 1989): A baseline study (258 employees), interviews with assaulted staff members (61) within 7 days after the assault and again after 6 weeks, and they also completed a questionnaire, a follow-up study of the assaulted staff, who filled in a questionnaire every week for 6 weeks, again after 6 months and 1 year after the assault. Response rate at 6 months was 84% and after 1 year it was 72%. Criteria for inclusion into the study were physical assaults from patients and some form of staff response. The primary purpose of the study was to describe short- and long-term reactions of the nursing staff member to physical assaults by a patient. These reactions are described in the paragraph on consequences of violence. The study also showed one risk factor namely that only 20% of the victims were primary staff for the violent patients, indicating that nursing staff members who were not well known to the patients were more exposed to assaults than were primary staff. The study met 14 out of 16 relevant evaluation criteria (Table 2). In two articles (1989 and 1993) Carmel and Hunter described a registerbased study of staff injuries due to patient assault in a large state hospital in California. The first article reports injuries from one specific year: 1986. The injuries were divided into two categories: (1) injuries caused directly by assaults from patients and (2) injuries sustained while controlling assaultive patients. The nursing staff reported most injuries that year: 16 injuries per 100 staff. Of these, 6.1 per 100 staff were from patient assault and 9.9 per 100 were from controlling violent patients.

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In the second article (1993) Carmel and Hunter report observations of injuries due to patient violence over a 5 year period from 1984 to 1989. During the longer period of observation it turned out that the psychiatrists had more injuries per year (6%) than the nursing staff (4.3%). There were no reported injuries on psychiatrists during the 1 year observation period (1986). The authors do not discuss why 1986 seems to be a more violence prone year for the nursing staff compared to the average for the 5 year period but the results shows the advantage of a long observation period. The study showed that most injuries occurred when the staff had to control a violent patient. Most injuries were reported at the emergency wards. The study also showed that 74% of the injuries from assaults were inflicted by patients known to the staff member. The average number of injuries per year was 50% higher among male nurses than among female nurses. The gender differences are discussed in both articles (Carmel & Hunter, 1989, 1993). The study met 5 out of 12 relevant evaluation criteria (Table 2). Characteristics of staff victims of patient assaults including inpatient, outpatient, and community residence staff were studied in Massachusetts (Flannery et al., 2001). The purpose of this study was to examine characteristics of staff victims of violence/threats of violence. Data was collected through interviews with assaulted staff from 1990 to 2000 by a team from the Assaulted Staff Action Program (ASAP). The results showed that in traditional state hospital settings less senior male mental health workers with less formal education and training had the highest risk of exposure to violence especially during restraining procedures. Nurses also had a higher risk during restraining procedures. The study met 6 out 13 relevant criteria, including references to other articles, which have information on the criteria not described in this article (Table 2). In an earlier study of the same population with the same method and procedure, substance abuse and subsequent violence towards staff was studied among psychiatric patients (Flannery et al., 2000). This was based on collection of data over 6 years. They found that patients with a past history of violence towards others and personal victimization were significantly more frequently associated with assaults on staff than were patients with either of the two past histories alone. When substance abuse disorder was added the association with assaults increased significantly. This study met 7 out of 12 relevant criteria (Table 2). A study of patient assaults in a psychiatric hospital in Canada was carried out over a 27 month period (Cooper & Mendonca, 1991). The purpose of the study was to determine the absolute and base rates of patient – nurse assaults and to describe some clinical characteristics of the assaulters. Violence was defined as intentional personal physical violence towards a nurse. The violence was rated in three degrees: no physical injury, minor injuries (bruises etc.), and large abrasions, etc. The method for collecting

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data, the variables included, and who collected the data are not described any further. The results showed that patients with a diagnosis of mental retardation and dementia were most often associated with assaultiveness. The study met 3 out of 12 relevant criteria (Table 2). Another Canadian study was carried out in a four-ward maximumsecurity psychiatric unit between 1979 and 1984 (Harris & Varney, 1986). The purpose of this study was to examine physically assaultive behaviour over an extended period of time. Assaultive incidents were included if they involved patient initiated intentional physical contact of a forceful nature between two or more persons. Ward reports of incidents were examined daily and patients involved, staff, and witnesses, when possible, were interviewed about time and causes of the incidents. Results showed that staff and the assaulters gave different reasons for the assaultive behaviour, especially of incidents where a staff member was directly involved. Most often the staff reported that they did not know why the assault had happened. The assaulters most often saw assaults as the result of teasing and direct provocation. Generally, both groups agreed that assaults were not a direct result of psychiatric symptomatology but rather a result of interpersonal conflicts. The researchers concluded that the assaultiveness was due to the interaction of environmental and internal factors. The study met 9 out of 13 relevant evaluation criteria (Table 2). In a 10-year prospective study, inpatient aggression was investigated in a Norwegian special unit for dangerous psychotic patients (Bjørkly, 1999). One of the purposes of the study was to identify and classify precipitants of aggressive incidents. A Report Form for Aggressive Episodes was used for each patient and after each episode to monitor the incidents. Aggression was defined and the report form included six sections for recording aggressive episodes: verbal and physical threats, and four sections on physical assaults. The hospital’s aggression incident register was used to distinguish between serious and less serious physical assaults. The report form was used for periods of 3 months at a time and after 1 year it was revised to include precipitants of aggressive behaviour. The nurse who observed the aggressive incident recorded the incident and at least one other staff member was consulted for an opinion. After the patients calmed down they were questioned about motives of their behaviour. The hospital’s safety overseer rated the severity of the assaults on a 3-point scale. The results of the study showed that 64% of the aggressive incidents took place in limit-setting situations, 25% happened when the patient was hallucinating, deluded, or otherwise unable to communicate with other people, and 4% were precipitated by physical contact. There was more than one precipitating factor in about one-third of the aggressive incidents. The study met 8 of 12 relevant evaluation criteria (Table 2).

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In a study of violence in psychiatric hospitals in the UK, Whittington and Wykes (1994) tested whether certain staff members were more prone to being assaulted. The study took place in 13 wards in two psychiatric hospitals. Sixty-five nurses were assaulted during the 14 week study period. They were compared to the rest of the staff. Questionnaires were filled in after each incident. Information of the control group was derived from hospital records. Assaultive patients were either interviewed or information was derived from staff or medical notes. The results did not support ‘‘proneness for violence’’ with regard to demographic data nor personality of the assaulted staff members. However, grade and age seemed to predict involvement in violent incidents and the patients tended to assault staff who were larger than themselves (Whittington & Wykes, 1994b). The study met 9 out of 12 relevant criteria (Table 2). Another British study was carried out in a locked ward of a psychiatric hospital in London (Aiken, 1984). Violent incidents were observed over a 6 month period in 1982. The aim of the study was to assess the usefulness in clinical practice of previous observations, that behavioural clues, along with patients past history of violence, and diagnosis predict future violence. Descriptions of the hospital, the ward and the staff were included in the study. Only violence that resulted in physical harm was included in the study. After a violent incident the staff filled in a standard incident form. The senior nursing officer graded this form according to the severity of the incident. The staff and the patient involved in the incident were interviewed afterwards and case notes were studied. Patients were interviewed about the reasons for the violence. A follow-up interview with the staff was conducted depending on the severity of the incident and the injury. Three aspects of the patient’s behaviour immediately prior to the incident were categorized to enable an arousal rating score and compared to the severity of the injuries received by staff. Results showed no significant association between patient diagnosis and severity of the injury. However, 18 out of the 19 patients involved in the violent incidents had a past history of violence against property or other persons. The results also showed that the patient’s posture and movement was the most powerful predictor of a violent incident. The study met 6 out of 15 relevant evaluation criteria (Table 2). A case-control study of assaultive behaviour by psychiatric patients in a Taiwanese psychiatric hospital was carried out in four acute wards (Chou, Lu, & Chang, 2001). The study was conducted over a 7 month period. When an assault was identified the researchers carried out a chart review and interviewed the nursing staff, using standardized aggression scales. The results showed that assaulted nurses were younger than the nonassaulted staff, had less working experience in a psychiatric ward, and they did not have training in prevention and management of assaults. The nonassaulted nurses had also received more training in identifying risk factors for

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violence, and in seclusion and restraint techniques, than the assaulted staff. Staff – patient conflicts were interactions that most frequently resulted in assault. The patients seemed to be more violent during active phases of psychosis. They did not find a significant association with alcohol abuse. Most assaults occurred during mealtime and in areas with a lot of ‘‘traffic’’. The study met 10 out of 12 relevant evaluation criteria (Table 2). Health care A Swedish prospective case-control intervention study of 47 health care workplaces, randomly assigned to either an intervention or a control group included risk analyses of violence (Arnetz & Arnetz, 2000). The purpose of the study was to evaluate all types of violent events, which were systematically registered and to test awareness of the risks of violence. The study included a baseline study to establish data concerning experience with violence at work, with an overall response rate of 77%, 1 year of registration of violent incidents in all workplaces, using the ‘‘Violent Incident Form’’, previously developed and tested by the authors (and described in another article), and interventions. A follow-up questionnaire after 1 year had an overall response rate of 68%. There was no significant difference between the intervention group and the control, except for number of years employed at the present workplace. Staff in the intervention group had worked longer. Except for the interventions all questionnaires were self-report. The results showed that age 4 40, male gender, and being a supervisor were risk factors for violence. Except for the response rate at follow-up, the study met all the evaluation criteria for the review (Table 1). In a descriptive, longitudinal cohort design violence towards nurses in two public emergency departments in Australia was investigated (Crilly et al., 2004). One hundred and eight nurses were included in the study. Four instruments were developed and tested in a pilot study and demographic data were compared to data from the Australian Institute of Health and Welfare. Seventy-one (66%) nurses participated in the baseline and 50 reported violence in the 5 month follow-up period. The study found no difference in demographic data between the nurses subjected to violence and the nurses who were not. Most of the violence took place in the evening (37%) and at night (21%) and the violent patients were often under the influence of alcohol (27%) or drugs (25%). The study met 12 out of 13 relevant evaluation criteria (Table 2). The service sector With the purpose to investigate repeated noncoincidental violent incidents, 1078 reports on violent incidents in English and American pubs

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from January 1992 till June 1995 was studied (Beale et al., 1999). The analyses showed that 20% of the incidents were followed by a new incident within 6 months. The risk of a new incident was highest within 3 – 4 days after the first incident and the risk was significantly increased up to 4 weeks after the first incident. It was not always clear whether the second incident was directly related to the initial incident, though. The study met all the relevant evaluation criteria (Table 2). In a prospective study of work-related violence (Fisher & Jacoby, 1992), 22 bus drivers from two London garages were studied in order to assess the outcomes. Risk of violence was also analysed. Out of the 22 drivers, the 20 who had been assaulted were from the same garage and so were the matched nonassaulted control group (matched on gender, age, nationality, and rank). Two of the victims were from another garage. The first assessment of victims took place between 8 weeks and 6 months after the assault and they were followed up 18 months later. There was no definition of assault. Fifteen (68%) of the victims were followed up. There was no control group at follow-up. Analyses showed that the risk of violence was highest for drivers on a specific route (the characteristics for this route were not stated, though), for driving at night between 6 and 9 p.m. The study also showed that drivers with a previous history of workrelated assaults were more likely to be assaulted again. The study met 11 out of the 17 possible criteria (Table 2). Cohort study A Danish study based on a random sample of the working population tested hypotheses on the long-term effect on the victims’ well-being, prediction of future violence, and other explanations of the association between violence and fatigue (Hogh et al., 2003). A cohort of 4961 respondents was interviewed by phone in 1990 and in 1995. Response rates were 90% at baseline and 84% at follow-up. There was no definition of violence. In 1990, 8% had been subjected to violence. Likewise in 1995, 8% of the respondents had been subjected to violence. Of these, 4% had also been subjected in 1990 (odds ratio, OR: 12.0). In 1990, violence was more prevalent among employees with client contact (OR: 10.7), employees with customer contact (OR: 3.8), and among teachers (OR: 3.0), compared to employees with no contact at work with other people than colleagues. The study met 13 out of the 16 relevant evaluation criteria (Table 2). Summary The studies either have no definitions of violence or have different definitions, which makes it difficult to compare the results. Most of the

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studies are carried out in psychiatric hospitals or wards. Two studies investigate ‘‘general’’ health care workplaces, two studies were carried out in the service sector, and one study is a population (a cohort) study. See Table 3 for a summary of causes and risk factors found in the studies according to the percentage of evaluation criteria met.

Studies on ‘‘consequences of violence and threats of violence at work’’ Five studies met the inclusion criteria for consequences of violence and are reviewed in this section. Psychiatric health care The British study in a locked ward of a psychiatric hospital in London (Aiken, 1984) also included results on consequences for the victims (for a description of the study, see the section on risk of violence). Results showed that there was a significant association between the severity of injury and degree of arousal by the patient. The results also showed that in 47% of the incidents, the staff member felt a change in attitude and anger towards the patient. This feeling changed to resentment and subsequently to fear of the patient. In the study by Ryan and Poster (1989; see the section on risks of violence), the purpose of the study was also to identify behavioural changes and to describe short- and long-term reactions. The reactions were measured on a 5-point scale ranging from no reaction to severe reactions. Acute reactions were experienced by 41%, and 18% stated that they had experienced moderate to strong reactions up till 6 weeks after the attack. The follow-up showed that 21% experienced reactions 6 months after the assault while 16% still had reactions 1 year after the incident. Anger was the most common short-term emotional reaction experienced by 40 – 50% of the nursing staff; 30 – 40% stated that they were anxious and felt sorry for the aggressor. Tension and increased body awareness were among the reported physiological reactions (40 – 50%). Some had these reactions up to 1 year after the assault. Fear of the ‘‘violent’’ patient and trouble understanding what had happened was experienced by 20 – 30%. At the 6 month follow-up, less than 10% had these kinds of reactions. Among the staff who had had considerable physical injuries some experienced moderate to severe reactions up to 1 year after the assault. Thirty-nine assaulted psychiatric nurses were compared to a control group—matched for age and occupational grade (Wykes & Whittington, 1998). The study was conducted at six acute psychiatric wards of a large London hospital. The study was divided into two phases and with three

TABLE 3 Summary of risk factors of violence grouped according to the percentage of evaluation criteria the studies met in the review Criteria met

Individual characteristics (staff)

Situation factors

Structural factors

4 75%

Male nurses (health care) (b) Age 4 40, young age (b, f) High rank (b) Psychiatric staff with less working experience (f) Previous exposure to violence (m)

A previous incident (c) Interpersonal conflicts (f, m) Patients (psychiatric) with psychosis (f) Alcohol was not a risk factor (f) Patients under influence of alcohol and drugs (h) Not being the primary staff (n)

During mealtime (f) Ward areas with ‘‘a lot of traffic’’ (f) Evening and night shift (h)

50% – 74%

Previous exposure to violence (i) Charge nurses and staff nurses (o) High rank (o) Middle age (o)

Having to use force towards a patient, i.e., restraining procedures, limit-setting (d) Psychiatric patients unable to communicate (d) Physical contact with psychiatric patient (d) Patients (psychiatric) with psychosis (d) Patients under influence of alcohol/drugs (h) Substance abuse in psychiatric patients with a past history of violence and victimization (k) Interpersonal conflicts (l) Interaction of environmental and internal factors (l)

Evening/night shifts (i) Work in certain places (certain bus routes) (i)

550%

Less formal education and training (j) Restraint of violent patients (j) Less senior mental health workers (j) Male staff (psychiatric care of male patients) (e)

Patients with a past history of violence (a) Patient posture and movement (a) Staff known to the patient (e) Patients with mental retardation/dementia (g) Having to use force towards a patient, i.e., restraining procedures, limit-setting (e)

Work in certain places (psychiatric and emergency hospital wards) (e)

1

1

The letters in parentheses refer to the references in Table 1.

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groups of participants. In the first phase, a baseline group of 26 nurses, who had not been assaulted within the past month and who worked at an intensive care unit, was studied. The purpose was to study the changes in reactions before and after an assault. In the second phase of the study, cases (39 assaulted nurses) were collected over a period of 6 months. They were examined twice—within 10 days after the assault and again approximately 1 month after the assault. Only some of these nurses were also included in the baseline group. A control group of 34 nurses, who had not been exposed to violence in the past 6 months, were established at the same time as the assaulted group. As far as possible they were matched for rank and gender. The purpose for choosing the above-mentioned groups was to compare the groups—not to follow a specific nurse over time. The criteria for inclusion into the study were patient-initiated physical contact between nurse and patient, which the nurse perceived as hostile or threatening. Verbal aggression was not included. Assaulted staff (39) were investigated for traumatic stress, psychological distress, a feeling of danger at the workplace, and physical injury and concurrent stressors. Two persons had symptoms of Posttraumatic Stress Disorder (PTSD). A deterioration in mental health and reduced control of anger were also reported. Psychological distress was reported more often after assaults that resulted in physical injury. Staff who were frequently assaulted, reported either significantly more or significantly less stress reactions than those who were assaulted only once did. The study met 16 out of the 17 criteria (Table 2). The service sector In the English prospective study of bus drivers from two London garages (Fisher & Jacoby, 1992), the victims of physical assault were assessed for psychiatric impairment, distress, and PTSD within 6 months and again after 18 months (see the section about risks of violence). The assessment included semistructured interviews about PTSD symptoms, and a questionnaire with two health scales and one personality scale. Only 15 victims (68%) were included in the follow-up study and none of the controls. It is not explained why the control group was not included in the follow-up. The results of the study showed a positive correlation between the seriousness of the assault and the duration of sick leave for the assaulted drivers; 20% had PTSD symptoms at the first interview, and 60% also had a mild depression. At the second interview after 18 months, 13% had PTSD symptoms. The measures of psychological reactions did not correlate with sick leave or other special events (not defined) in the past year. At follow-up one person had developed PTSD symptoms, which he did not show any signs of at the first interview. However, he had witnessed a knife-assault during the follow-up period.

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Cohort study The Danish cohort study also tested a hypothesis on long-term effects of exposure to violence at work and found a linear association between exposure to violence and fatigue 5 years later. When controlled for gender and age, social support, contact with other people than colleagues at work, and conflicts, there was still a significant association between violence in 1990 and fatigue in 1995. However, conflicts seemed to partly mediate this effect (Hogh et al., 2003). Summary All but one of the studies about consequences of violence met more than half of the evaluation criteria. The five studies show that being subjected to violence may have serious long-term consequences for the victims (Table 4).

DISCUSSION In the present systematic review 16 prospective longitudinal studies are presented and evaluated according to a number of criteria. The studies report of individual, situational, and structural risk factors of violence and they show that being subjected to violence may have serious acute and longterm consequences for the health and well-being of the victim. Two studies report of PTSD symptoms in victims of violence. One reason for the relatively few longitudinal studies on risk factors and consequences of workplace violence may be that it is very costly to design and carry out such studies. A longitudinal design with the intention to follow the respondents over a period of time also requires personal identification information on the individual level, which is not possible or very difficult to obtain in many countries. A few methodological shortcomings in the reviewed studies need to be mentioned. The first criterion asked in the current evaluation is whether the study has a baseline. This is included in the design of only five of the studies. A reason for this may be that it is costly. However, it is still important to include a baseline study to minimize the possibility that some or all of the outcomes may have been caused by factors other than a violent incident. Another shortcoming is that some of the studies do not state a definition of the phenomenon studied and those that do have very different definitions of work-related violence, which makes it difficult to compare the studies. This may be reflected in the fact that there has not been an international consensus on a definition of violence at work. It has been discussed in the literature (LeBlanc & Barling, 2005; Lipscomb & Love, 1992) and broad definitions have been suggested including both physical and psychological

306 TABLE 4 Summary of consequences of exposure to violence grouped according to the percentage of evaluation criteria the studies met in the review

Criteria met

Cognitive symptoms

Emotional symptoms

Psychosomatic symptoms

Other reactions

4 75%

Difficulty understanding what had happened (n) 1

Anger (n, p) Feeling sorry for patient (n) Poor mental health (p) Distress (p) Fatigue (m) Anxiety (n) Fear of assaultive patient (n)

Tension (n) Increased body awareness (n)

Reactions after 6 months and 1 year (n) Symptoms of PTSD (p) Reactions longer lasting if victim received physical injury (n, p) Frequently assaulted staff reported either more or less stress reactions than others (p)

50 – 74%

5 50%

1

Depressive symptoms (i)

Change in attitude towards the patient (a)

Anger/resentment towards the patient (a) Fear of the patient (a)

The letters in parentheses refer to the references in Table 1.

Symptoms of PTSD (i) Sick leave—duration correlated with seriousness of assault (i) Sick leave did not correlate with reactions at follow-up (i)

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violence (e.g., Di Martino, Hoel, & Cooper, 2003; Wynne, Clarkin, Cox, & Griffiths, 1996). There is an ongoing debate as to whether a control trial is always the best model for research when studying traumatic events, which by definition are sudden and unexpected (Everly, Flannery, & Mitchell, 2000). Likewise, it can be difficult to design a study including a control group before and during the study period in workplaces where the risk of violence is fairly high, such as psychiatric wards. Another important source of difficulty and a potential bias in a case-control study is the precise definition of who counts as a ‘‘case’’ since even one misallocated subject may substantially influence the results (Greenhalg, 1997). However, a control group can be used to minimize the possibility that outcomes might have occurred for other reasons than exposure to violence, or to assess the role of individual characteristics or coping strategies in exposure to violence and outcomes (Hogh & Mikkelsen, in press; Moran, 1998). Another type of methodological problem in some of the studies is the rather low response rates, which can lead to over- or underrepresentation of the exposed staff. This may have an impact on the significance of the reported risk factors and consequences of violence. In the current review, very few of the risk factors of violence are reported in more than one study and this may of course reflect the questions asked in the different studies. It is not possible to investigate all aspects in every study and some risk factors may be specific of a certain workplace. When it comes to person-related risk factors, the reviewed studies report several types of individual characteristics, which may increase the risk of exposure to violence at work. One such factor is previous exposure to violence, which is found in two of the reviewed studies. One study found violent incidents to be predictors of new incidents. Theoretically, it has been suggested that exposure to negative behaviour at work such as violence may illicit a vicious circle that could explain the recurrence of exposure (Felson, 1992; Tedeschi & Felson, 1994). A similar explanation is proposed by Whittington and Wykes (1994a). They suggest that the feeling of distress after exposure to violence affects the nurses’ behaviour towards patients and that this may generate patient anger and aggression. For instance, coping strategies such as confrontational and/or escape-avoidance coping may be linked to behaviours that increase the risk of recurrent violence. Confronting strategies may be expressing anger at the patient overtly or using inappropriate physical restraint. Avoidance strategies may be expressed by reducing contact or avoiding the patient (Whittington & Wykes, 1994a). A further explanation may be reflected in the fact that three studies reported interpersonal conflicts to be a predictor of violence. In their study, Whittington and Wykes (1994a) also found that most of the repeated assaults involved the same pair of staff victim and patient, and the violence

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may thus be a result of both the individual emotions of the pair and the working situation on the ward. Two studies found that male nurses are more at risk of violence than the female nurses, which is rather puzzling, since there are more women working in health care than men in most countries. One of the studies suggests that men are more at risk because they work with male patients (Carmel et al., 1989, 1993). Another explanation might be that male nurses are put in the front line, when force or limit setting is used—a risk factor mentioned in more than one study. Some of the risk factors, for instance age, found in the different studies are inconsistent. One study found middle age to be a predictor of violence, whereas two other studies found that young age and age under 40 is a predictor. However, the young age may reflect other risk factors such as less formal education and/or training and staff with less working experience. The middle age risk factor may reflect high rank, which is found to be a risk factor in two studies. These observations confirm previous research about individual and work-related risk factors for violence in the health care sector (Menckel & Viitasara, 2002; Viitasara et al., 2003). Another inconsistent risk factor is the patient/client-related factors such as influence of alcohol or drugs and different diagnoses. This, together with the other situation and structural risk factors may reflect that some risk factors are specific for certain workplaces. A conclusion of the somewhat inconsistent risk factors of violence at work could be that more than one risk factor need to be present for an interaction to result in violence. In a recent cross-sectional study, Viitasara and her colleagues (2003) found that different risk factors may add up to a pattern or be a characteristic of a certain type of workplace. The results of this study also revealed a complex picture of individual and work-related risk factors without any unequivocal pattern. That is, a particular factor that proved to be a risk for an occupational group did not manifest itself as a general risk factor for all occupational groups. On the contrary, each separate group appeared to have their own sets of risk factors. That is, work-related violence occurs in a specific situation, but broader situational and structural factors shape the context for what takes place and also influence the nature of the circumstances. Accordingly, when studying workplace violence a theoretical model should be used, which involves the identification of risk factors at three levels, i.e., individual level, which refers to specific factors, workplace level, which refers to situational factors, and organizational level, which refers to structural factors (Viitasara & Menckel, 2002). The reviewed studies showed that being exposed to violence at work may result in variety of different long-term health symptoms including symptoms of PTSD. However, very few symptoms are mentioned in more than one study and some of the studies also show that not all the victims have short-

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or long-term reactions when exposed to violence. This may illustrate that, according to transactional models of stress (e.g., Cohen & Edwards, 1989; Lazarus & Folkman, 1991), the outcome of a stressful transaction (such as violence) is mediated by the individual’s appraisal and coping. Thus, individual differences in how employees perceive and cope with violence at work may partly explain why some employees develop severe stress symptoms following exposure to violence while others seem to be relatively unaffected (Hogh & Mikkelsen, in press; Moran, 1998). For instance, an association has previously been found between exposure to violence and a weak sense of coherence (SOC) and it was also found that SOC mediated the relationship between violence and different stress reactions (Hogh & Mikkelsen, in press). According to Antonovsky, SOC is a stable global construct, which comprises three interrelated aspects: sense of comprehensibility, meaningfulness, and manageability. Supposedly, SOC is stable after approximately 30 years of age (Antonovsky, 1987a, 1993). SOC affects how individuals perceive the world and the events that happen to them as well as the extent to which they perceive these events as controllable. The core hypothesis of the concept is that the stronger the person’s sense of coherence, the more adequate will be his or her capacity to cope with psychosocial stressors in the work environment as well as in private life (Antonovsky, 1987b). However, prospective studies have found SOC to be unstable after victimization due to trauma (Snekkevik, Anke, Stanghelle, & Fugl-Meyer, 2003), and accidents, chronic illness, and traumatic events may change a person’s world view and thus their SOC (Schnyder, Bu¨chi, Sensky, & Klaghofer, 2000). The study linking violence to a weak SOC was crosssectional, thus this association needs to be studied longitudinally. In such a study one hypothesis might be that SOC may change after exposure to violence at work and thus have an influence on the relationship between exposure to violence and potential health effects. Another hypothesis could be that employees with a weak SOC may appraise a stressor as more threatening than employees with a strong SOC (Antonovsky, 2003) and they may cope less well with, e.g., conflicts at work (Spector, Zapf, Chen, & Frese, 2000). This may increase their risk of exposure and recurrent exposure to violence and threats of violence at work.

CONCLUSIONS The present article has reviewed literature in the area of violence at work. The focus has been on risk factors and consequences of nonfatal violence. Compared to the amount of research on workplace violence, very few longitudinal and prospective studies have been carried out. Sixteen longitudinal studies are included in this review: 15 of the studies reported different risk factors of violence or threats of violence and 5 reported acute

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and long-term consequences. Very few of the risk factors were mentioned in more than one study. Among the individual characteristics of the staff only young age and previous exposure were found to be risk factors in more than one study. When looking at situational risk factors, interpersonal conflicts, having to use force towards a patient, and dealing with psychotic patients were risk factors reported in more than one study. Among the structural risk factors, working in the evening or at night was found in two studies. The five studies that explored consequences of exposure to violence or threats of violence clearly document that exposure to violence at work has serious long-term consequences for the staff, with a variety of different cognitive, emotional, and psychosomatic symptoms and symptoms of PTSD, symptoms that may also have an impact on the workplace and on work performance. Anger, fear, and PTSD symptoms were reported in more than one study. There still is a need for longitudinal studies that, to a further extent, assess how the different risk factors interact and result in violence and threats of violence against staff. There is also a need for studies with a longitudinal design that assess the associations between work conditions and exposure to violence and the consequences for the organization as a whole, especially in high-risk organizations. Furthermore, in many of the studies physical injury was an inclusion criteria in the definition of a violent incident, so there is a need for more studies that include consequences of assaults without injuries and also consequences of threats of violence. For successful prevention, the worksite violence management should focus on the three levels of risk factors, i.e., individual, situational, and structural, and serve three prevention purposes, i.e., primary, secondary, and tertiary. Primary prevention means the reduction of risk of violence, such as making the environment safer and/or ‘‘strengthening’’ personnel so that they may handle the risk situations more effectively. This can be achieved through training and education in how incidents of violence and threats of violence can be managed and avoided. Secondary prevention means that the extent and duration of any incident of violence is reduced so that as few people as possible become involved in an incident. Tertiary prevention refers to efforts made retrospectively, meaning that any exposed person receives support and assistance following a traumatic experience, which may strengthen their capability to cope with future potential risks of violence at work (Viitasara, 2004).

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