Do statutory holidays impact the number of opioid-related hospitalizations among Canadian adults? Findings from a national case-crossover study.

Abstract

In Canada, emergency department visits, hospitalizations, and deaths due to opioid use have risen substantially in recent years. While these events have exhibited seasonal and day of week patterns, there have been no attempts to investigate the extent to which statutory holidays influence these patterns, particularly opioid-related hospitalizations. We applied a time-stratified case-crossover study design to investigate whether statutory holidays were predictive of opioid-related hospitalizations using the Canadian Discharge Abstract Database (excluding Quebec) for fiscal years 2011/2012 to 2016/2017. This design controls for day of week effects. We restricted analyses to opioid hospitalizations (ICD-10 codes: F11.x, T40.0-T40.4, and T40.6) among individuals 15years and older. Conditional logistic regression models were fit to estimate the odds of opioid-related hospitalization on holidays relative to non-holidays. We examined these patterns across different holiday types, namely social gathering holidays (e.g., Canada Day) and family holidays (e.g., Christmas). Stratified analyses were done to identify whether these associations varied by agegroup and sex. We identified a total of 59,965 opioid-related hospitalizations. Overall, we found a 12% reduced odds in opioid hospitalizations on holidays (odds ratio [OR] = 0.88, 95% CI 0.83, 0.93) relative to non-holidays. Similar reductions were observed for both family (OR = 0.86, 95% CI 0.79, 0.93) and social gathering holidays (OR = 0.90, 95% CI 0.84, 0.96). No substantive differences were noted by agegroup or sex. Our findings support the hypothesis that opioid-related hospitalizations occur less frequently on statutory holidays. This knowledge may help inform healthcare resources and health promotion activities to reduce the impacts of opioid use.