The association of gender and persistent opioid use following an acute pain event: a retrospective population based study of renal colic

Introduction — This study aims to explore gender-related differences in persistent opioid use following an acute pain episode and evaluate potential explanatory variables.

Methods — This retrospective population-based study using administrative databases included all opioid-naïve patients in Ontario with renal colic between 2013 and 2017. The primary outcome was to assess any association between persistent opioid use at 3-6 months by gender. Key confounding covariates and explanatory variables examined included both care- and patient-related factors, specifically past evidence of mental health diagnoses.

Results — The dataset of 64,240 males and 37,656 females demonstrated that 8.7% of males and 9.6% of females had evidence of persistent opioid use 3-6 months after presentation (OR 1.11, 95% CI 1.05, 1.17). Females had a higher incidence of mental health services utilization [44.5% vs 29.6% (p<0.001)] and were more likely to be on a provincial disability program [5.1% vs 3.8% (p<0.001)]. Age, income quintile, mental health diagnoses and dose of opioid prescribed were associated with the primary outcome in both genders. On adjusted analysis for multiple confounding and explanatory variables, females were still more likely than males to demonstrate persistent opioid use (OR 1.07, 95% CI 1.01, 1.13) with even more pronounced associations at 1-2 years.

Interpretation — After controlling for key covariates, females are at slightly higher risk of demonstrating long term opioid use following an episode of renal colic. Evidence of prior mental health service utilization and acute colic care did not appear to significantly explain these observations.