Risk of suicide in medical and related occupational groups: A national study based on Danish case population-based registers

Abstract

Background

Suicide risk may be elevated in ‘medical’ occupational groups, although results of studies are inconsistent. National data are required to examine this issue. It is also important to investigate the possible contribution of psychiatric disorder and access to specific suicide methods.

Methods

In a nested case–control design we used data from Danish national registers for 1981–2006 to examine risk of suicide in nurses, physicians, dentists, pharmacists and veterinary surgeons compared to teachers and the general population, and associations with psychiatric service contact and suicide methods.

Results

Crude age- and gender-adjusted rate ratios for suicide compared to teachers were significantly elevated in nurses (RR 1.90, 95% CI 1.63–2.21), physicians (RR 1.87, 95% CI 1.55–2.26), dentists (RR 2.10, 95% CI 1.58–2.79) and pharmacists (RR 1.91, 95% CI 1.26–2.87), but not veterinary surgeons. Risk was also elevated in nurses, physicians and dentists compared with the rest of the general population, the relative risk increasing following adjustments for psychiatric service contact, marital status, gross income and labour market status. Results were similar in both genders. The elevated risk in nurses and dentists decreased during the study period. Elevated risks were not associated with greater psychiatric service contact. Medicinal drugs were commonly used for suicide by nurses, physicians and pharmacists.

Limitations

The study was based in one country.

Conclusions

Risk of suicide is increased in nurses, physicians, dentists and pharmacists in Denmark. This is not reflected in excess psychiatric service contact. Ready access to medicinal drugs may influence risk in nurses, physicians and pharmacists.

Introduction

There is accumulating evidence that risk of suicide is increased in certain occupational groups, especially those involved in medically-related professions. Studies in different countries have indicated that suicide risk is elevated in physicians (Agerbo et al., 2007, Hem et al., 2005a, Kelly and Bunting, 1998, Meltzer et al., 2008, Schernhammer and Colditz, 2004), especially in females (Hawton et al., 2001, Lindeman et al., 1997a, Petersen and Burnett, 2008, Schernhammer and Colditz, 2004). However, in other investigations this has not been confirmed, or the reverse found in male physicians (Petersen and Burnett, 2008), especially in recent studies (Meltzer et al., 2008). Suicide risk has also been found to be elevated in nurses in some, but not all studies (Hawton and Vislisel, 1999, Meltzer et al., 2008). Other medically-related occupational groups in which risk of suicide has been reported as increased include dentists and pharmacists, although findings of studies differ, especially for dentists (Alexander, 2001, Boxer et al., 1995, Meltzer et al., 2008, Stefansson and Wicks, 1991). Also, an elevated risk of suicide has been reported in veterinary surgeons in several countries (Platt et al., 2010), including the UK (Charlton, 1995, Kelly and Bunting, 1998, Mellanby, 2005, Stark et al., 2006), USA (Blair and Hayes, 1982), Australia (Jones-Fairnie et al., 2008) and Norway (Hem et al., 2005b). However, some studies of risk of suicide in veterinary surgeons have been based on local data and/or relatively small numbers of deaths.

Suicide is strongly associated with psychiatric disorder (Cavanagh et al., 2003, Hawton and Van Heeringen, 2009). Therefore, one explanation for the increased risk of suicide in medical occupational groups could be an increased rate of psychiatric disorder compared with other occupations. Whilst prevalence of psychiatric disorders has been investigated in psychological autopsy studies of suicides in nurses (Hawton et al., 2002) and doctors (Hawton et al., 2004), rarely has this been examined in case–control studies within occupational groups (Hawton et al., 2002), and in comparisons with other occupational groups.

Greater access to means for suicide in medical and medically-related occupational groups has been proposed as another explanation for their increased suicide risk (Aasland et al., 2001, Hawton et al., 2000, Kelly and Bunting, 1998). All medically-related occupational groups have greater access to medicinal drugs than the general population. There have been few studies, however, in which the methods used for suicide in specific medically-related occupational groups have been compared to those used in the general population (Hawton et al., 2000).

We have used data from the national registers for Denmark to examine the relative risk of suicide in nurses, physicians, dentists, pharmacists and veterinary surgeons compared to the risk in teachers and the rest of the general population using a case–control design. We have also investigated whether any elevated risk in these occupational groups is related to prevalence of psychiatric disorder as indicated by contact with psychiatric services. Finally, we have examined the use of specific methods of suicide in these professional groups compared with their use for suicide in other occupational groups.