write a theoretical framework

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T he 2003 outbreak of severeacute respiratory syndrome(SARS) was associated with significant emotional distress in 18% to 57% of health care workers during

and shortly after the outbreak period (1–5). Less information is available about the longer-term impact of health care work during the SARS outbreak. The Impact of SARS Study

found that one to two years after the outbreak, professional burnout and symptoms of traumatic stress, anxiety, and depression remained somewhat elevated among Toronto hospital workers compared with colleagues in settings that did not treat SARS pa- tients (6). A key question about this finding is whether persistent post- SARS elevation of distress among some health care workers interferes with their social and occupational function. Distress is normative; how- ever, in rare instances, a psychiatric disorder is diagnosed when psycho- logical distress persists over time and interferes with social and occupation- al function (7).

Working in a hospital during the SARS outbreak may have represented a psychological trauma for some health care workers. Typically, 80% to 90% of people exposed to trauma do not de- velop posttraumatic stress disorder (PTSD) (8). However, several factors may have increased the perceived per- sonal risk associated with SARS (9), in- cluding the uncertainty of dealing with an illness of unknown cause and mode of transmission before the identifica- tion of the SARS coronavirus (10–13) and the disease’s rapid global spread and significant mortality.

Understanding the psychiatric im- pact of SARS on hospital workers in terms of both distress and disorder is relevant to the well-being of large numbers of exposed health care workers who continue to work in their profession and who could be at risk of exposure to future emerging infec- tions, including pandemic influenza

Prevalence of Psychiatric Disorders Among Toronto Hospital Workers One to Two Years After the SARS Outbreak WWiilllliiaamm JJ.. LLaanncceeee,, PPhh..DD.. RRoobbeerrtt GG.. MMaauunnddeerr,, MM..DD.. DDaavviidd SS.. GGoollddbblloooomm,, MM..DD.. aanndd CCooaauutthhoorrss ffoorr tthhee IImmppaacctt ooff SSAARRSS SSttuuddyy

Dr. Lancee and Dr. Maunder are affiliated with the Department of Psychiatry, Mount Sinai Hospital, Toronto, Ontario, and with the University of Toronto. Dr. Goldbloom is with the Centre for Addiction and Mental Health and the Department of Psychiatry, Uni- versity of Toronto. Additional coauthors are listed in the box on the next page. Send cor- respondence to Dr. Maunder at the Department of Psychiatry, Mount Sinai Hospital, 600 University Ave., Rm. 915, Toronto, Ontario, Canada M5G 1X5 (e-mail: rmaunder@mtsi nai.on.ca)

Objective: This study aimed to determine the incidence of psychiatric disorders among health care workers in Toronto in the one- to two-year period after the 2003 outbreak of severe acute respiratory syndrome (SARS) and to test predicted risk factors. Methods: New-onset episodes of psychiatric disorders were assessed among 139 health care workers by using the Structured Clinical Interview for DSM-IV and the Clini- cian-Administered PTSD Scale. Past history of psychiatric illness, years of health care experience, and the perception of adequate training and support were tested as predictors of the incidence of new-onset episodes of psychiatric disorders after the SARS outbreak. Results: The lifetime prevalence of any depressive, anxiety, or substance use diagno- sis was 30%. Only one health care worker who identified the SARS ex- perience as a traumatic event was diagnosed as having PTSD. New episodes of psychiatric disorders occurred among seven health care workers (5%). New episodes of psychiatric disorders were directly asso- ciated with a history of having a psychiatric disorder before the SARS outbreak (p=.02) and inversely associated with years of health care ex- perience (p=.03) and the perceived adequacy of training and support (p=.03). Conclusions: Incidence of new episodes of psychiatric disorders after the SARS outbreak were similar to or lower than community inci- dence rates, which may indicate the resilience of health care workers who continued to work in hospitals one to two years after the SARS out- break. In preparation for future events, such as pandemic influenza, training and support may bolster the resilience of health care workers who are at higher risk by virtue of their psychiatric history and fewer years of health care experience. (Psychiatric Services 59:91–95, 2008)

(14). In our previous study, we meas- ured distress in a large sample of health care workers (6). In the study reported here, we investigated disor- ders, as reflected by the prevalence of PTSD and other psychiatric diag- noses, among workers at SARS-af- fected hospitals one to two years after the resolution of the SARS outbreak. We tested the hypothesis that new episodes of psychiatric disorders after SARS would be more frequent among health care workers who had a history of psychiatric illness. In the previous analysis of distress (6), we found that having more years of health care experience and an indi- vidual’s perception of having had ade- quate training were protective. Therefore, we also tested the hypoth- esis that these variables would protect against new episodes of psychiatric disorders, beyond the impact of a his- tory of psychiatric illness.

Methods The Impact of SARS Study was con- ducted in Toronto and in Hamilton, Canada, between October 23, 2004, and September 30, 2005. This report concerns the health care workers in Toronto, where almost all of Canada’s 438 suspected and probable SARS patients were identified. All nine of the academic and community hospi- tals in Toronto that participated in this study treated SARS patients. Eli- gible health care workers included nurses in medical or surgical inpa- tient units and all staff of intensive care units, emergency departments, and SARS isolation units. This study was approved by the research ethics boards of each hospital. After partici- pants were given a complete descrip- tion of the study, written informed consent was obtained.

Of the 587 Toronto participants who completed several self-report

outcome scales in part 1 of the Im- pact of SARS Study (6), 139 (24%) volunteered to participate in a diag- nostic interview and were given the Clinician-Administered PTSD Scale (CAPS). Of these, 133 (23% of the overall sample) also participated in a SCID interview. Interviewed individ- uals received $50.

Survey questionnaires included the 15-item version of the Impact of Events Scale (IES) (15,16), the Kessler Psychological Distress Scale (K10) (17), the emotional exhaustion scale of the Maslach Burnout Inven- tory (18–20), and self-report of any increase since the SARS outbreak in smoking, drinking alcoholic bever- ages, using nonprescription drugs, or “other activities that could interfere with your work or relationships.” Perception of the adequacy of train- ing, protection, and support with re- spect to SARS was measured by us- ing a previously described instru- ment (5,21,22).

Axis I diagnoses were determined with the Structured Clinical Inter- view for DSM-IV (SCID) (23–25), excluding the psychosis and PTSD modules, which was administered by trained interviewers. For each en- dorsed disorder, the interviewer de- termined whether symptoms preced- ed SARS, followed SARS, or both and whether the symptoms were present in the past month.

The PTSD section of the SCID was replaced with the CAPS (26,27). The CAPS is a structured interview that assesses PTSD diagnostic status and symptom severity. The CAPS has ex- cellent reliability (greater than the SCID), yielding consistent scores across items, raters, and testing occa- sions (28). There is also strong evi- dence of convergent and discriminant validity, diagnostic utility, and sensi- tivity to clinical change. The CAPS was administered one or two times: first, for the most severe past trauma of any kind (including SARS as a can- didate event) and second, for the most recent trauma if it was different from the most severe past trauma as- sessed in the first administration. For each of the one or two events, symp- toms were placed in two time frames: ever since the trauma and in the past month.

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CCooaauutthhoorrss ffoorr tthhee IImmppaacctt ooff SSAARRSS SSttuuddyy

The following individuals served as full coauthors for this article but could not be listed on the title page because of space limitations.

Kenneth E. Balderson, M.D. Department of Psychiatry, St. Michael’s Hos- pital and University of Toronto

Jocelyn P. Bennett, Ph.D., R.N. Department of Nursing, Mount Sinai Hospi- tal and University of Toronto

Bjug Borgundvaag Jr., M.D., Ph.D. Emergency Department, Mount Sinai Hospital and Department of Family Medicine, Uni- versity of Toronto

Susan Evans, R.N., M.Sc.N. Scarborough Hospital, Toronto Christopher M. B. Fernandes, M.D. Department of Medicine, University of West-

ern Ontario Mona Gupta, M.D. Department of Psychiatry, Women’s College

Hospital and University of Toronto Linda McGillis Hall, Ph.D., R.N. Department of Nursing, University of Toronto Jonathan J. Hunter, M.D. Department of Psychiatry, Mount Sinai Hos-

pital and University of Toronto Lynn M. Nagle, Ph.D., R.N. Department of Nursing, Mount Sinai Hospital Clare Pain, M.D. Department of Psychiatry, Mount Sinai Hos-

pital and University of Toronto Sonia S. Peczeniuk, M.Sc. Rouge Valley Health System, Toronto Glenna Raymond, M.B.A., R.N. Whitby Mental Health Centre, Whitby,

Ontario Nancy Read, M.Sc. St. Michael’s Hospital, Toronto Sean B. Rourke, Ph.D. Department of Psychiatry, St. Michael’s Hos-

pital and University of Toronto Rosalie J. Steinberg, M.Sc. Department of Psychiatry, Mount Sinai Hos-

pital and University of Toronto Thomas E. Stewart, M.D. Department of Medicine, Mount Sinai Hos-

pital and University of Toronto Susan VanDeVelde-Coke, R.N. Sunnybrook Health Sciences Centre, Toronto Georgina H. Veldhorst, M.B.A., R.N. North York General Hospital, Toronto Donald A. Wasylenki, M.D., M.Sc. Department of Psychiatry, St. Michael’s Hos-

pital and University of Toronto

We determined the prevalence of lifetime axis I psychiatric disorders before the SARS outbreak. The prevalence of new episodes of a psy- chiatric disorder was determined and compared among participants with or without a previous episode of a psychiatric disorder. Because panic attacks were frequently re- ported by the health care workers in this study even in the absence of panic disorder, the prevalence of post-SARS panic attacks was also compared among participants with or without a previous episode of a psychiatric disorder.

Logistic regression analysis was used to determine the contributions of previous episodes of a psychiatric disorder, perception of adequate training and support, and years of health care experience to the occur- rence of a new episode of a psychi- atric disorder post-SARS. A two- tailed test of probability with p less than .05 indicated statistical signifi- cance. Statistical analysis was per- formed with the SPSS, version 15.0.

Results As shown in Table 1, of 139 partici- pants, 87% were female, and 73% of the sample were married or living in common-law relationships. The mean age was 45.0 years, and the mean number of years of health care expe- rience was 20.4. Of the 139 partici- pants, 112 (81%) were Western Euro- pean; 11 (8%) were Asian, Southeast Asian, or Philippine; eight (6%) were African or West Indian; seven (5%) were Eastern European; and one (<1%) was from another group. A to- tal of 103 participants (74%) were nurses, and 15 (11%) were clerical staff. The remaining 21 participants (15%) were employed in 15 other hospital job types. During the SARS outbreak, 88 participants (63%) had worked five or more shifts in the emergency department, intensive care unit, or a SARS isolation unit. A majority (105 participants, or 76%) reported contact with SARS patients.

As shown in Table 1, compared with health care workers who com- pleted the survey portion of the Im- pact of SARS Study but were not in- terviewed, participants who agreed to be interviewed were significantly old-

er and more experienced in health care but did not differ by gender or job type or in any of several aspects of psychological distress.

The interval between the date when the last SARS patient was dis- charged or died and study participa- tion ranged from 13 to 22 months (median 18). The CAPS interview, which was administered to 139 health care workers, identified four (3%) with a lifetime history of PTSD. Of these, two met criteria for current PTSD and one identified the SARS experience as the most severe traumatic event. Among the 133 par- ticipants who were administered the SCID interview, the lifetime preva- lence of DSM-IV axis I diagnoses that were present before the SARS outbreak was as follows: major de- pression, 14 participants (11%); pan- ic disorder, eight (6%); generalized anxiety disorder, four (3%); social phobia, eight (6%); agoraphobia, three (2%); specific phobias, five (4%); somatoform disorders, four (3%); and substance abuse or de- pendence, six (5%). A total of 40 health care workers (30%) met diag- nostic criteria for at least one of these disorders during their lifetime before the SARS outbreak.

In the time since the SARS out- break, 25 health care workers (19%) experienced panic attacks. Thirteen of these participants had a psychiatric history identified by the structured interviews. That is, 13 of the 40 work- ers (33%) with a psychiatric history experienced panic attacks after SARS, compared with 12 of the 93 workers (13%) with no identified psy- chiatric history (p=.01). As shown in Table 2, new onset of major depres- sion and new onset of any psychiatric disorder were also more common among health care workers with a his- tory of psychiatric illness. Altogether, seven health care workers (5%) expe- rienced a new episode of a psychiatric disorder in the one to two years after the resolution of the SARS outbreak.

We used logistic regression to de- termine whether the variables that were associated with psychological distress in a previous analysis (6) were also associated with episodes of a psy- chiatric disorder. The results showed a significant association (R2=.13, p=.002) of the onset of any axis I di- agnosis after SARS with a previous psychiatric history (β=.22, p=.02) and an inverse (protective) association with years of health care experience (β=–.21, p=.03) and with the percep-

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TTaabbllee 11

Characteristics of Toronto health care workers in the Impact of SARS study who completed only the survey and those who were also interviewed

Survey only Survey and inter- (N=448) view (N=139)

Characteristic N % N % p

Demographic Age (M±SD) 41.3±10.2 45.0±9.6 <.001 Health care experience (M±SD years) 16.0±10.2 20.4±10.7 <.001 Female 384 86 121 87 .69 Nurse 315 70 103 74 .39

Psychological distress Increase in substance use or inter-

personal problems since SARS 72 20 28 23 .61 Posttraumatic stress symptoms

(M±SD score)a 12.8±10.3 13.6±9.9 .40 Depression and anxiety symptoms

(M±SD score)b 16.5±6.6 16.5±6.6 .95 Professional burnout (M±SD score)c 20.8±13.1 20.2±12.2 .64

a As measured by the Impact of Events Scale. Possible scores range from 0 to 45, with higher scores indicating greater traumatic stress.

b As measured by the Kessler Psychological Distress Scale. Possible scores range from 10 to 50, with higher scores indicating more anxiety and depressive symptoms.

c As measured by the emotional exhaustion scale of the Maslach Burnout Inventory. Possible scores range from 0 to 54, with higher scores indicating greater burnout.

tion of being adequately trained and supported by the hospital or clinic (β=–.20, p=.03).

Discussion This study found that one to two years after the resolution of the SARS out- break in Canada, the incidence of new episodes of major depression among health care workers who were still working was 4% (five of 133 par- ticipants) and the incidence of new- onset PTSD was 2%. The incidence of any new onset of a psychiatric dis- order was 5%. These incidence rates appear to be lower than those found in the general population. For exam- ple, the estimated annual incidence of major depression in Canada for women aged 25 to 44 has been re- ported to be 4.5%, and for women aged 45 to 64 it is 4.1% (28). The in- cidence of depression also appears to be lower than the recently reported one-year rate of 9% for Canadian nurses (29).

Given the previous report of signif- icantly elevated long-term psycholog- ical distress among Toronto health care workers compared with col- leagues at hospitals that did not treat SARS patients (6), interpretation of this low incidence of new onset of episodes of a psychiatric disorder re- quires consideration of the distinction between distress and psychiatric dis- order and attention to both the char- acteristics of the health care workers studied and the methodological limi- tations of the study.

The lifetime prevalence of psychi- atric diagnoses among the health

care workers studied is similar to that in the Canadian community (30) with respect to major depression (health care workers, 10.5%; Cana- da, 12.2%), panic disorder (6.0% and 3.7%), social phobia (6.0% and 8.1%), and agoraphobia (2.3% and 1.5%). The lifetime prevalence of PTSD in an American community sample was 7.8% (10.4% among women) (8), markedly higher than the prevalence in this study (2.9%). Rates of substance abuse or depend- ence are more difficult to compare with the Canadian community, where prevalence been described by using different criteria and time pe- riods; however, lifetime rates among the health care workers appear to be lower than those found in the com- munity (31). Thus there was no indi- cation of elevated susceptibility to psychiatric disorders among health care workers who participated in this study. The lifetime prevalence data are inconclusive with respect to the possibility of elevated resilience among the health care workers who participated in this study.

A critical question is whether the health care workers who participated in this study are representative of their colleagues. There are two points in the recruitment process that re- quire scrutiny. First, were health care workers who participated in the Im- pact of SARS Study similar to those who chose not to participate? The re- sults of a previously reported repre- sentativeness survey confirmed that health care workers who participated were similar to colleagues at the same

hospitals who did not participate with respect to age, years of health care ex- perience, job type, gender, and over- all perception of the negative impact of SARS (6). Second, were the health care workers who participated in structured interviews similar to those who completed only the survey? All of the information available from the survey questionnaires confirms that psychological distress was similar among health care workers who were interviewed and those who were not (Table 1). The evidence supports this sample as being representative of health care workers at the participat- ing hospitals.

It is important to note that this study did not include health care workers who stopped working, moved, or were not working because of long-term disability during the study period. As a result, mental health problems severe enough to re- sult in persistent disability were not included. Thus, although the results of this study are consistent with the interpretation that the SARS out- break did not increase risk for psychi- atric disorders in health care workers, caution is required. Studies of exces- sive disability and sick-time after the SARS outbreak would be useful but are not currently available. The selec- tion of working health care workers may explain why the overall rate of major depressive episodes since SARS is lower than that recently re- ported for Canadian nurses (29). It is also important to note that confi- dence intervals on prevalence rates are large because of the sample size. For example, the upper limit of the 95% confidence interval of the rate of new episodes of major depression af- ter SARS is 8.6%.

Why was there increased psycho- logical distress (6) but no concomi- tant increase in psychiatric disorders in health care workers after SARS? The critical difference between dis- tress and psychiatric disorder is the impact of that distress on social and occupational function. We interpret our findings as a demonstration of the resilience of health care workers who continue to work in their field after their experience with SARS. Attribut- ing this result to resilience is consis- tent with the finding that having more

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Prevalence of new onset of mental illness since resolution of the SARS outbreak among 133 Toronto health care workers, by whether or not they had a history of psychiatric illness

No mental illness Any mental illness before SARS before SARS (N=93) (N=40)

New onset after SARS N % N % pa

Major depressive episode 1 1 4 10 .02 Panic disorder 0 — 1 3 .29 Posttraumatic stress disorder 1 1 1 5 .49 Substance abuse or dependence 0 — 2 5 .09 Any new axis I mental disorder 2 2 7 18 .03

a Fisher’s exact test

years of experience in health care work was associated with a lower inci- dence of psychiatric disorders. These findings are also consistent with pre- vious studies of mass trauma, which have found a lower of incidence of PTSD after natural disasters than af- ter events of malicious human intent and a lower incidence of PTSD in communities with high levels of social support (32).

Conclusions The study confirmed the prediction that new episodes of psychiatric dis- orders would be more prevalent among health care workers with a history of psychiatric illness. In a health care setting, especially in the context of preparing for an influenza pandemic and other emergent dis- eases, this finding highlights the rel- evance of health care workers’ being attentive to their own personal risk in order to respond quickly to emer- gent symptoms of anxiety or depres- sion. Furthermore, this study con- firms the hypothesis that health care workers who feel well supported and trained by their employer experience better mental health over the long term. Among the predictors of risk in this study, training and support are the factors that are most amenable to preventive intervention within an or- ganization. This finding suggests that even among health care workers who are at elevated risk of a psychiatric disorder by virtue of unmodifiable factors (such as having less experi- ence or having a history of a psychi- atric disorder), efforts by a hospital to offer effective practical and emo- tional support and to provide train- ing in novel tasks and personal pro- tection significantly enhance re- silience.

Acknowledgments and disclosures

This study was funded by an operating grant SAR-67807 from the Canadian Institutes of Health Research.

The authors report no competing interests.

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