Background
Terrorist attacks have been shown to affect mental and physical health of exposed individuals including symptoms of anxiety and depression [
1], post-traumatic stress disorder [
2‐
4], and musculoskeletal and gastrointestinal pain [
5]. Such health problems may affect the workability of workers and contribute to sickness absence [
4,
6‐
9].
Sickness absence in the aftermath of a workplace terrorist attack may be associated with injury or psychological responses to the attack itself, and/or with individual and work-related conditions. To our knowledge, no previous studies have examined sickness absence after a workplace terrorist attack in relation to both disaster exposure, and psychological and social working conditions. We hypothesize that working conditions may moderate effects of exposure on sickness absence in positive and negative ways.
Mechanisms
Being subjected to terror at work may alter workers’ appraisal of his or her workplace in many ways. The Job Demands-Resources model (JD-R) [
10,
11], and The Conservation of Resources (COR) theory [
12,
13] may provide a theoretical framework for understanding how stressors may affect worker health, and sickness absence. The JD-R model postulates
job demands as stressors associated with costs, for example negative health consequences. However,
job resources may help prevent such negative effects. Job resources are defined as specific physical, psychological, social, and organizational factors of work that may stimulate growth and reduce job demands [
10]. For example, if an employee perceive his or her work responsibilities and expectations to be clearly defined, and are provided with autonomy to decide how and when the work should be done, the coping of negative work events, may be bearable compared to if the employee are not allowed to make such adjustments during the workday. Thus, it is reasonable to assume that work factors like autonomy, or support from superior or co-workers may moderate potential adverse health effects of exposure to workplace terrorism on sickness absence. For example, close monitoring and dialogs between employees and supervisor may facilitate recovery, and prevent sickness absence. The COR theory is about loss and gain [
12]. The goal is to gain and maintain as many resources as possible (e.g. skills, employment, energy). The theory postulates that stressful conditions, in our case exposure to a workplace terrorist attack, or poor working conditions, will lead to resource losses. Employing resources for coping with such losses is according to Hobfòll (1989) stressful in itself. Thus, it is reasonable to assume that exposure to the terrorist attack combined with role conflicts may put an additional load on the worker, which requires coping resources that in turn may drain energy and induce health problems or sickness absence.
Workplace terrorism
The body of knowledge of work-related terrorism is limited. A study of employees at Pentagon in the aftermath of the September 11 attacks, 2001, showed that directly exposed workers reported lowered sense of safety at work, especially those who showed posttraumatic stress symptoms or symptoms of depression [
14]. Similar results were obtained in a study of Norwegian ministerial employees after the 22th of July, bombing in Oslo in 2011 [
15]. Feeling less safe, or experiencing PTSD or symptoms of depression may alter worker’ appraisal of psychological and social working conditions like job demands, leadership or role expectations. Furthermore, traumatized employees may cope with the situation by avoiding the workplace all together, for example through sick leave. A study of Norwegian ministerial employees from pre- to post-disaster showed that perception of leadership generally was stable over time, but workers who experienced posttraumatic stress symptoms perceived their immediate leader to be less supportive [
16]. Furthermore, higher levels of social support, and leader support have been shown to be associated with a more rapid decline in worker psychological distress in the aftermath of the 22nd of July Oslo attack [
17].
Workplace terrorism and sickness absence
To our knowledge, only two previous studies have examined associations between exposure to a workplace terrorist attack and subsequent sickness absence. A study of people exposed to the September 11, 2001 attacks in New York showed no statistical significant association between exposure and sickness absence due to psychological or physical symptoms [
18]. However, a study of ministerial employees in Norway who were exposed to the 22nd of July, 2011 Oslo bombing showed an increase in sickness absence rates over a two-year period after the attack compared to before the attack [
19]. Thus, there is limited evidence of an association between exposure to workplace terrorism and subsequent sickness absence.
Systematic reviews show that working conditions may be important to the mental health of workers in positive and negative ways [
20‐
23]. Furthermore, a systematic review concluded that there is strong evidence that job control and control over working hours may decrease the risk of sickness absence. There are limited evidence for an association between role conflict and role clarity and sickness absence [
24]. Another systematic review concluded that there is some evidence that work overload and pressure, lack of control over work, lack of participation in decisions, poor social support and unclear management and work role were associated with increased sickness absence [
20]. Based on previous research findings, we elucidate the following specific work factors as potential moderating factors of exposure to the blast on subsequent sickness absence: Role clarity, role conflict, control of decision, control of work pace, support from immediate superior, and support from co-workers.
Discussion
The present study showed that psychological and social work factors appear to be important both for the odds of becoming sick-listed, and for the duration of the sickness absence period in the aftermath of a workplace terrorist attack. The present study also showed a complex moderating relationship between exposure to the terrorist attack, psychological and social work factors and effects on subsequent sickness absence.
Directly exposure to the terrorist attack was associated both with increased odds of becoming sick-listed and increased duration of the sickness absence period (also see Hansen et al., under review). A valid basis for comparison of results is currently lacking. A study by Osinubi and collegues (2008) did not find and association between exposure to the September 11 attack and subsequent sickness absence due to psychological or physical diagnoses. However, the current study did not analyze diagnosis-specific sickness absence. Furthermore, sickness absence in Norway may not be comparable to sickness absence in the USA because of highly different rules of sickness absence in the two countries. In Norway, loss of income due to sickness absence is compensated by the Norwegian National Insurance for maximum six times the Norwegian national insurance schemes’ basic amount of 93,634 NOK. Hence, workers do not suffer extensive economic losses during the first year absent from work. Income above this amount will not be compensated.
Control of decision and leader- and co-worker support were associated with decreased odds of becoming sick-listed. Thus, our findings are in line with previous findings in the field [
20,
24]. Support from superior was associated with decreased duration of sickness absence. Hence, job control and support may act as protective factors against becoming sick-listed in the first place, and as protective of long-term sickness absence. Role conflict, on the other hand, appeared to increase the odds of becoming sick-listed, and prolong the duration of sickness absence. These findings support previous findings in the field [
20,
24].
Effects of exposure to a workplace terrorist attack on subsequent sickness absence appeared to interact in a complex manner with psychological and social working conditions. Exposure to the blast appeared to increase the odds of sickness absence when role clarity was average or high, but not when role clarity was low. Role clarity is usually considered as protective of sickness absence [
25], and this notion have gained some support empirically [
20,
24]. There is no obvious reason for why exposure should increase the odds of sickness absence with higher levels of role clarity. However, a speculation may be that being highly aware of one’s responsibilities and expectations actually may act as a work load when coping with psychological reactions following a workplace terrorist attack, especially when work ability may be reduced. Another explanation may be that the initial level of sickness absence may be higher among workers with low role clarity than workers with high role clarity. Consequently, the effect of exposure on sickness absence may not be equally visible with different levels of role clarity as the effect is overshadowed by high initial levels of sickness absence in this group [
29]. The current findings partly support previous findings of associations between role clarity and sickness absence [
20,
24].
As expected, exposure to the bomb explosion appeared to increase the rates of sickness absence when control of work pace was low, but not when average or high. Hence, facilitating worker autonomy may protect against long-term sickness absence in the aftermath of terrorism or other stressful events at the workplace.
Potential modifying roles of role conflict (
p = 0.078), support from superior (
p = 0.062), and support from co-workers (
p = 0.071) on sickness absence were marginally not statistically significant, and might be worth wile further investigation in future studies as well. We believe the current results gives an insight into the complexity in studying and interpret moderation when it comes to the issue of type I and type II errors [
28], as well as studying moderation on multiplicative scales [
29]. Role conflict is generally considered to be a risk factor for ill-health [
25]. The current findings support this notion (Table
2) and are in line with previous studies [
24,
30,
31]. However, effects of exposure to a workplace terrorist attack on subsequent sickness absence seems to be more pronounced with lower levels of role conflict than higher. As discussed earlier, this may be explained by initially higher levels of sickness absence among those who experience high role conflict overshadowing the effect of exposure.
Support from superior is generally considered to be a protective factor of ill-health [
25]. However, the empirical evidence is mixed with regard to sickness absence [
24]. The current study showed that the odds of becoming sick-listed decreased with increasing levels of support from superior. As with our previous findings, the effect of exposure on sickness absence seems to be more pronounced with higher levels of leader-support, which might be an indication of leader-support initially acting as a protective factor of sickness absence. Hence, facilitating leader-support might be important for reducing the risk of sickness absence.
Strengths and limitations of the study
Strengths of the current study were its fairly high sample size, the prospective study design, and the combination of different data sources. By combining survey data of exposures (predictor variables) and registry data on sickness absence (outcomes), the present study minimizes the risk of observing spurious associations that could be attributed to common method bias [
32]. However, as the predictor variables of the present study were assessed by self-report measures, we cannot rule out the potential problems reporting bias associated with such measures poses [
32]. The QPS
Nordic [
25] instrument used in the current study to assess job control, role clarity, role conflict, support from immediate superior, and support from co-workers should be relatively insensitive to respondents’ personality dispositions or emotions. Negative/positive connotations in response scales, using verbal labels for all response categories, and reversing some of the items were measures employed in construction of the items to reduce the risk of reporting bias. The respondents were asked how often a situation occurs instead of degrees of agreement or satisfaction [
25]. The cronbach’s alpha coefficient for role conflict was .66, thus the precision of the measurement may have been weakened in the current study.
The response rate at survey-baseline was 56% and thus above the estimated average for organizational surveys [
33]. In terms of selection bias, we know that females were more likely to respond at baseline compared to males. A low response rate may pose a threat to internal validity through self-selection mechanisms if participating is a common effect of both exposure and outcome [
32]. Of the 1974 workers who responded at baseline, 83.6% gave their consent to link survey data to data on sickness absence, which may be considered highly acceptable in terms of representativeness. Still, lower education and being female was associated with non-consent. Although, exposure to the terrorist attack may have been a focus of motivation to participate in the survey, adverse working conditions and sickness absence were likely not.
There is a chance that workers who became sick-listed in the time period from the terrorist attack to baseline never was reached when conducting the survey 10 months after the attack. Furthermore, three out of seventeen ministries declined to participate in the survey, and may pose a risk of selection bias.
The current data on sickness absence includes doctor-certified sickness absence only, not self-reported sickness absence. In Norway, employees are allowed to be absent from work for up to three consecutive days, four times a year without a sick-leave note from a doctor. If the organization of employment is a part of “The agreement on inclusive working conditions”, a employee is allowed to be absent from work for up to eight consecutive days, for a maximum of 21 days a year without a sick-leave note from a doctor. It is likely that the overall absenteeism from work due to health complaints was even higher than the current study’s estimate.
A debated issue in research on sickness absence is whether or not one should include previous sickness absence in analyses of future sickness absence [
34]. At baseline, there is already an association between exposure to the bomb explosion, working conditions and sickness absence (10 months after the attack). Also, employees may have become sick-listed in the period from immediately after the blast to baseline. We believe the likelihood of a substantial increase in sickness absence from 10 to 22 months after the attack is low because the level of sickness absence was already high for some employees at baseline. Adjustment for previous sickness absence in the regression models rules out the variance in sickness absence at baseline explained by the predictors. Hence, we may risk underestimation of the true effect of exposure to the blast and working conditions on sickness absence.
The current study aimed at elucidating potential moderating effects of working conditions on effects of exposure to the bomb explosion on sickness absence. However, as Table
1 suggests, exposure to the blast seemed to affect perceptions of working conditions at baseline. We cannot rule out the possibility that working conditions may mediate effects of exposure to the blast on subsequent sickness absence.
Conclusions
The present study showed that exposure to the bomb explosion, and role conflict were risk factors for subsequent sickness absence. Control over decision, control over work pacing, and support from superior and co-workers were found to be protective factors of sickness absence. We found support for moderating effects of role clarity and control over work pace, and weaker evidence of moderating effects of role conflict, support from co-workers, and support from leader. The patterns of interactions are complex, and conclusions should be drawn with caution. Directly and indirectly exposed workers may benefit from good working conditions in order to lower the risk of sickness absence and shorten sickness absence periods. Organizations in general, and organizations exposed to workplace terrorism, would benefit from striving for good psychological and social working conditions both as preventions against illness and sickness absence, and as measures in the aftermath of a workplace terrorist attack.
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