COIOSDeep risk insights through multi-disciplinary research across the globe
city with high rise buildings and bridge during daytime
Item refines Peer-reviewed Added

Accidental overdose admissions in New South Wales and later premature death by cause

Among 14,036 people hospitalised for accidental overdose in New South Wales, deaths ran at 3.5 times the expected rate.

The study followed 14,036 people admitted to New South Wales hospitals with non-fatal accidental poisoning, 2011-2020. Poisonings involved drugs linked to non-medical use and dependence, including opioids and benzodiazepines; median follow-up was 3.9 years. Deaths were compared with expected values from official statistics, giving standardised mortality ratios (SMR) and years of life lost (YLL). There were 2,588 deaths; all-cause SMR was 3.5, rising to 59.5 for accidental poisoning and 10.5 for suicide. Natural causes made up 64.0% of YLL; median YLL per death was 21.2 in males, 15.2 in females. The cohort relies on hospital coding and covers only overdoses that led to admission.

Why it is interesting: Most life-years lost after a hospitalised overdose came from natural causes such as cancer and respiratory disease, not further poisoning. Infectious and respiratory death rates were six to seven times those expected.

Source
Addiction, 25 October 2026
Paper
Accidental overdose admissions and premature death: A large population-based data-linkage cohort study in New South Wales, Australia (PAVLOVA 4)
Authors
Noghrehchi F, Cairns R, Roberts DM, Morley KC, Haber PS, Buckley NA
DOI
10.1111/add.70604
Type
Peer-reviewed article
Design
Population-based data-linkage cohort, 14 036 people with index non-fatal accidental poisoning, all NSW hospitals 2011-2020, median 3.9 years follow-up, 2588 deaths; SMRs and YLL against official statistics
Verdict
Refines prior evidence
Driver
Alcohol and drug use
Free full text
Free to read at the publisher
Abstract — the authors' own words, CC BY

Background and aims

People with substance use disorders have reduced life-expectancy; however, risks of premature death from injuries and natural causes following an accidental overdose are not well characterised. This study aimed to estimate risk of premature death (by cause and over time), and disease burden following hospitalised accidental overdose. Design

An observational study using the Poisoning And enVenomation Linkage to evaluate Outcomes and clinical Variation in Australia (PAVLOVA) cohort. Setting

A population-based data-linkage including admissions from all public and private hospitals in New South Wales, Australia (population ~8 million), 2011-2020. Participants

14 036 individuals [median age 43.5 years, interquartile range (IQR) = 29.4-61.8 years, 46.7% female, n = 6557] with an index non-fatal accidental poisoning, as defined by hospital coding, followed for a median of 3.9 years (IQR = 1.7-6.3). We restricted our analysis to people with accidental poisonings with prescription and illicit drugs that are associated with non-medical use and dependence, including opioids and benzodiazepines. Measurements

Standardised mortality ratio (SMR) by cause (natural causes stratified by body system, and external causes stratified by intent and mechanism), SMR over time (post-index poisoning), years of life lost (YLL) by cause, age and sex. SMR and YLL were calculated based on expected values generated using official statistics. Results

Of the 14 036 people included, there were 2588 deaths. Death was more likely in individuals with accidental poisoning compared with the general population [SMR = 3.5, 95% confidence interval (CI) = 3.4-3.7]. SMRs were highest for external causes (SMR = 12.8, 95% CI = 11.5-14.1), including accidental poisoning (SMR = 59.5, 95% CI = 51.7-67.3) and suicide (SMR = 10.5, 95% CI = 8.2-12.9). Death was also more likely across all natural causes, particularly infectious (SMR = 7.0, 95% CI = 5.1-8.9) and respiratory diseases (SMR = 6.2, 95% CI = 5.4-6.9). Median YLL per death was 21.2 (IQR = 10.0-35.6) and 15.2 (IQR = 7.2-30.2) for males and females, respectively. The main contributors to YLL were natural causes (64.0%): neoplasms (19.5%), circulatory (12.2%) and respiratory disease (11.1%). The remainder of YLL was from external causes (36.0%): mainly accidental poisoning (22.4%). Summary

People in New South Wales, Australia, who experience an accidental overdose appear to have an increased risk of death over subsequent years, but particularly in the first month, compared with the general population; however, accidental poisoning accounts for only 22% of years of life lost, with death from natural causes being much more common.

Other drivers in Behavioural science