Introduction: Chronic pain can be debilitating, distressing and isolating, and effective treatment options are limited. Prescription opioid medicines are a common treatment modality, however, opioids are associated with a range of adverse effects including dependence and overdose. Both chronic pain conditions and prescription opioid use have been associated with risk of suicide death. There is a growing global focus on deprescribing opioid medicines; however, concerns have been raised that undertaking deprescribing may lead to further distress and place consumers at increased risk of adverse outcomes. There is limited and conflicting evidence about associations between opioid discontinuation and fatal adverse outcomes. This study aims to investigate the association between prescription opioid discontinuation among long-term opioid users and death due to suicide.
Methods: A nested case-control study was undertaken within a population-based cohort study linking dispensing data to health and mortality datasets for 371,048 New South Wales adults prescribed opioids for ≥6-months between 01/07/2003-31/12/2018. Cases were individuals with a suicide death, matched using risk-set sampling to ten controls by age, sex, and time. Opioid discontinuation, versus ongoing use, was measured using time-varying periods of opioid exposure quantified from dispensing records. Covariates assessed in multivariate models included history of mental health conditions, prior hospital presentation for non-fatal self-harm, and psychotropic medicine use.
Results: Over the study period, 523 people died by suicide (median age 50-years (IQR 39-66), 368 male (70.4%)) and were matched to 5230 controls. Compared to people with ongoing opioid use, discontinuation was not associated with an increased odds of a suicide death (adjusted OR 0.88, 95% CI 0.72-1.07). Prior hospitalisation for suicide or non-fatal self-harm was associated with increased odds of a suicide death, independent of opioid deprescribing, suggesting more could be done following these hospitalisations to prevent subsequent fatal outcomes.
Discussions and Conclusions: In this population-based study of people using opioids long-term, opioid discontinuation was not associated with suicide death. As the first study of its kind conducted outside North America, these findings demonstrate that discontinuing opioid use is not inherently linked to suicide-related deaths and the findings have important implications for guidelines aimed at minimising risks associated with long-term opioid therapy.