BACKGROUND
Suicide by drug poisoning is potentially preventable; however, evidence on associated risk factors by sex is limited.

AIM
To assist in understanding how individual and social contextual factors, and specific drugs, influence risk of suicide compared to non-suicide drug poisoning deaths, and how this differs by sex.

METHODS
Data were extracted from the National Drug-Related Deaths Index. Analysis included univariable and multivariable logistic regression to estimate unadjusted and adjusted odds ratios (OR) and 95% confidence intervals (CI) for factors associated with suicide drug poisoning deaths (SDPD) (primary outcome) compared with non-suicide drug poisoning deaths (NSDPD) and stratified by sex.

RESULTS
SDPD accounted for 240 (22%) of 1114 poisoning deaths, the majority among men (n = 147, 61%). Increasing age, mental ill health (AOR 7.85, 95% CI: 5.46-11.28), chronic pain (AOR 5.57, 95% CI: 3.28-9.46), and history of previous overdose (AOR 5.06, 95% CI: 3.39-7.56) were associated with increased odds of SDPD, with similar results for both sexes. The main drugs associated with SDPD were non-opioid analgesics (OR 4.06 [95% CI 2.66-6.18]), antipsychotics (OR 2.42 [95% CI 1.63-3.60]) and antidepressants (OR 2.18 [95% CI 1.59-2.97]). Pregabalin was associated with SDPD among women only.

LIMITATIONS
Secondary analysis of coronial data on drug poisoning deaths therefore findings may not be relevant to suicide deaths in general.

CONCLUSIONS
Ongoing monitoring for signs of suicidal intent in individuals with mental illness, chronic pain, overdose, and/or prescribed mental health medications may identify individuals in need of additional intervention.