Suicide by occupation: does access to means increase the risk?

OBJECTIVE

To examine suicide by identified occupational groups in New Zealand over a period of 30 years, focusing on groups predicted to have high suicide rates because of access to and familiarity with particular methods of suicide.

METHOD

Suicide data (including open verdicts) for the period 1973-2004 were examined, excluding 1996 and 1997 for which occupational data were not available. Occupational groups of interest were dentists, doctors, farmers (including farm workers), hunters and cullers, military personnel, nurses, pharmacists, police and veterinarians. Crude mortality rates were calculated based on numbers in each occupational group at each quinquennial census, 1976-2001. Standardized mortality ratios were calculated using suicide rates in all employed groups (the standard population).

RESULTS

Few of the occupations investigated had high risks of suicide as assessed by standardized mortality ratios, and some were at lower risk than the total employed population. Standardized mortality ratios were elevated for male nurses (1.7; 95% CI: 1.2-2.5), female nurses (1.3; 95% CI: 1.0-1.6), male hunters and cullers (3.0; 95% CI: 1.7-4.8), and female pharmacists (2.5; 95% CI: 0.8-5.9). Doctors, farmers and veterinarians were not at high risk, and men in the police and armed forces were at low risk. Access to means appeared to have influenced the method chosen. Nurses, doctors and pharmacists were more likely to use poisoning than were other employed people (3, 4 and 5 times respectively, compared with all others employed). Farmers and hunters and cullers were more than twice as likely as all others employed to use firearms.

CONCLUSIONS

Access to means may be less important in some circumstances than in others, perhaps because of the presence of other factors that confer protection. Nevertheless, among the groups we studied with access to lethal means were three groups whose risk of suicide has so far received little attention in New Zealand: nurses, female pharmacists, and hunters and cullers.