(220) Predictors of persistent opioid use in Australian primary care: a retrospective cohort study, 2018 – 2022

Background: Opioids have a limited role in the treatment of non-cancer pain, with greater risks of adverse outcomes when prescribed in long-term. However, very little is known about the factors associated with long-term opioid use.

Objectives: The aim of this study was to examine the predictors of persistent opioid use (‘persistence’) in people initiating opioids for non-cancer pain in Australian primary care.

Methods: This retrospective cohort study included people prescribed opioid analgesics between 2018-2022 using data accessed through the Population Level Analysis and Reporting (POLAR) database. Persistence was defined as receiving opioid prescriptions for at least 90 days with a gap of less than 60 days between subsequent prescriptions.

Results: The sample consisted of 343,023 people initiating opioids for non-cancer pain; of these, 16,527 (4.8%) initiated persistent opioid use. Multivariable logistic regression showed that the predictors of persistence included older age (≥75 vs 15-44 years: adjusted odds ratio: 1.67, 95% CI: 1.58-1.78), concessional beneficiary status (1.78, 1.71-1.86), diagnosis of substance use disorder (1.44, 1.22-1.71) and chronic pain (2.05, 1.85-2.27), initiation with buprenorphine (1.95, 1.73-2.20), long-acting opioids (2.07, 1.90-2.25) and high opioid quantity (total OME of ≥750mg vs < 100mg: 7.75, 6.89-8.72), provision of repeat/refill opioid prescriptions at initiation (2.94, 2.77-3.12), and prescription of gabapentinoids (1.59, 1.50-1.68), benzodiazepines (1.43, 1.38-1.50) and z-drugs (1.61, 1.46-1.78).

Conclusions: These findings add to the limited evidence of individual-level factors associated with persistent opioid use. Further research is needed to understand the clinical outcomes of persistence in people with these risk factors to support the safe and effective prescribing of opioids.