Risk factors for suicide and other deaths following hospital treated self-poisoning in Australia.

Abstract

To analyze the risk factors for suicide, premature death and all-cause death in a representative population of hospital-treated deliberate self-poisoning patients. A prospective cohort study using data-linkage between the Hunter Area Toxicology Service Database and the National Death Index of the Australian Institute of Health and Welfare, from January 1991 to December 2000. There were 4105 subjects, of whom 228 (5.6%) died, 122 (2.9%) by premature death and 58 (1.4%) by suicide. The probability of suicide after 10 years follow-up was 2%. The adjusted hazard ratios (95% CI) for suicide were: 'disorders usually diagnosed in infancy, childhood and adolescence', 5.28 (95% CI = 2.04-13.65): male gender, 4.25 (95% CI = 2.21-8.14); discharge to involuntary psychiatric hospital admission, 3.20 (95% CI = 1.78-5.76); and increasing age, 1.02 (95% CI = 1.01-1.04). Men and women showed different patterns of multivariate risks, although increased risk with increasing age and discharge to an involuntary psychiatric admission was true for both. The standardized all-cause mortality ratio (95% CI) was: for men, 6.42 (95% CI = 5.44-7.57), and for women 4.39 (95% CI = 3.56-5.41). The standardized suicide mortality ratio (95% CI) was: for men, 20.55 (95% CI = 15.24-27.73), and for women 22.95 (95% CI = 13.82-38.11). Men and women have different risk factors for subsequent suicide after self-poisoning. Hospital-treated self-poisoning patients have increased risk of subsequent suicide, premature and all-cause death. Psychiatric assessment, leading to discharge decisions, is worthwhile in identifying patients at long-term risk of suicide, premature and all-cause death.