OBJECTIVES: We aimed to determine the rate of new persistent opioid use in New Zealand (NZ) after trauma 1^st January 2007 to 31^st December 2019.

METHODS: This was a retrospective population-based study. We included patients of any age who were admitted with trauma to any NZ hospital. Patients were excluded if they were not dispensed opioids after discharge, had prior history of opioid use, or diagnosed with opioid misuse. Patients who died or had recurrent trauma during follow up were also excluded. All patients were followed for 365 days. The primary outcome was the rate and predictors of persistent opioid use, defined as dispensing of any opioids after discharge within seven days and an additional dispensing of opioids between 91-365 days. Predictors were assessed using multivariable regression analysis.

RESULTS: 177,200 individuals were dispensed opioids on discharge; of these the rate of persistent opioid use was 15.3% (n=27,060). Significant predictors included switching of opioid type (adjusted odds ratio (aOR)=2.62; 95% confidence interval (CI) 2.51-2.73), higher comorbidity burden, pre-trauma non-opioid analgesics use (aOR=1.59; 95% CI 1.55-1.64), smoking (1.42; 95% CI 1.33-1.51), pre-trauma hypnotic use (aOR=1.33; 95% CI 1.27-1.39), dispensed slow-release opioid preparation post-trauma (aOR=1.32; 95% CI 1.26-1.39), older age, female sex (aOR=1.12; 95% CI 1.09-1.15), length of stay >1 day (aOR=1.10; 95% CI 1.06-1.14), site of trauma, and opioid type. Conversely, patients who underwent surgery was negatively associated with persistent opioid use (aOR=0.88; 95% CI 0.85-0.91).

CONCLUSIONS: One in seven opioid naïve patients who were acutely exposed to opioids after trauma became persistent users. Our findings suggest irrespective of site of trauma there are factors that may minimize risk of persistent opioid use. We recommend avoiding the use of slow-release opioid preparations on discharge from hospital after trauma if an opioid is deemed necessary and avoid unnecessary switching of opioids thereafter.