The risk of death after hospitalisation following intentional self-poisoning: a retrospective observational study (PAVLOVA-2).

Objectives: To estimate the risk of death after hospitalisation with non-fatal intentional self-poisoning in New South Wales, and to estimate the associated number of years of life lost.

Study design: Retrospective observational study; analysis of Poisoning And enVenomation Linkage to evaluate Outcomes and clinical Variation in Australia (PAVLOVA) study data.

Setting, participants: All index admissions to New South Wales public and private hospitals of people after non-fatal intentional self-poisoning (ie, were discharged from the index admission alive), 1 January 2011 - 30 September 2020.

Main outcome measures: Standardised mortality ratio (compared with general population mortality rate; SMR), overall, and by cause of death (data available only for 2011-2018); years of life lost (YLL) overall, and by cause of death (2011-2018), age group, and sex.

Results: Index admissions of people with non-fatal intentional self-poisoning were identified for 48 951 people; their median age was 32.8 years (interquartile range [IQR], 20.8-47.5 years), 30 274 were girls or women (61.8%), and 3449 died during follow-up (median, 4.9 years; IQR, 2.7-7.3 years). The all-cause SMR was 3.1 (95% confidence interval [CI], 3.0-3.2); by cause of death, the SMR was highest for external cause deaths (16.8; 95% CI, 15.9-17.8), including accidental poisoning (30.3; 95% CI, 27.4-33.2) and suicide deaths (25.1; 95% CI, 23.2-27.1). Among natural causes of death, the SMR was highest for infectious and parasitic diseases (5.4; 95% CI, 3.9-6.8), digestive diseases (4.2; 95% CI, 3.4-5.0), and respiratory diseases (3.0; 95% CI, 2.5-3.4). The estimated overall premature mortality burden was 110 301.4 YLL; the median value per death was similar for women (31.1 YLL; IQR, 15.0-43.0 YLL) and men (33.2 YLL; IQR, 19.7-44.9 YLL). During 2011-2018, the total mortality burden was 79 821.6 YLL; by cause of death, the major contributors were deaths from suicide (26 945.2 YLL; 33.8%), accidental poisoning (17 436.1 YLL; 21.8%), other injuries (6026.8 YLL; 7.5%), and natural causes (29 413.5 years; 36.8%).

Conclusions: The risk of death is markedly higher after hospitalisation with intentional self-poisoning than for the general population, but suicide deaths only cause about one-third of the mortality burden in terms of lost years of life; deaths from accidental poisoning and natural causes are also major contributors. Referrals to specialist psychiatric and physical health care and brief interventions for treating psychiatric and substance use conditions are appropriate after hospitalisation with intentional self-poisoning.