Non-Suicidal Deaths Following Hospital-Treated Self-Poisoning

Abstract

Objective: To quantify the non-suicidal mortality subsequent to hospital treated selfpoisoning, and to identify risk factors for non-suicidal death. Method: A prospective longitudinal cohort design was used, with data-linkage between the Hunter Area Toxicology Service database and the National Death Index. All patients with deliberate self-poisoning for a 10-year period (1991–2000) were studied and the first episode in the period was used as the index episode. The outcomes were: accidental, ‘natural’ and non-suicidal death, with follow-up for the study duration. Results: There were 4044 patients studied, and 170 (4.2%) of these had non-suicidal death; 64 were accidental and 106 were ‘natural’ cause deaths. The standardized mortality ratio (95% CI) for non-suicidal death for males, females and combined were 4.98 (4.08–6.07), 3.78 (3.0–4.75) and 4.20 (3.62–4.88), respectively. The increased mortality was apparent for both males and females, and was more marked in the younger age groups. For non-suicidal death the adjusted hazard ratio (95% CI) for increased risk were: increasing age 1.07 (1.06–1.08), male gender 1.77 (1.24–2.52), psychiatric diagnosis of substance related disorder 1.49 (1.03–2.16), prescription of a respiratory drug 2.69 (1.31–5.55), and prescription of an antidiabetic drug 1.95 (0.93–4.07), while psychiatric diagnosis of adjustment disorder 0.64 (0.38–1.053) was associated with decreased risk. Conclusions: Patients who present with self-poisoning have increased mortality from accidental and ‘natural’ causes. Long-term treatment goals for these patients need to address non-suicide mortality in addition to suicide mortality.