Outcomes Related to New Persistent Opioid Use after Surgery or Trauma: A population-based Cohort Study.

OBJECTIVES: To evaluate the impact of persistent opioid use (POU) following surgery or trauma on health outcomes using linked data.

SUMMARY BACKGROUND DATA: Surgery and trauma can lead to POU, characterised by continuous opioid consumption following hospital discharge. Outside the US, there is a lack of population-based studies on POU outcomes in opioid-naïve patients following these events.

METHOD: We included opioid-naïve patients who were dispensed opioids after being discharged following admission for surgery or trauma to any New Zealand (NZ) hospital from 2007-2019. Differences in outcomes between individuals with and without POU were assessed between 180-360 days after discharge. The primary outcome was all-cause mortality, the secondary outcomes were all-cause and opioid-related hospitalisation, and Days Alive and Out of Hospital (DAOH). Cox and quantile multivariable regression models were used to examine the association between POU and outcomes.

RESULTS: Overall, 298,928 surgical and 206,663 trauma patients were included in the final analyses, and 17,779 (5.9%) surgical and 17,867 (8.6%) trauma patients developed POU. POU was significantly associated with increased risk of all-cause mortality (surgical, aHR=6.59; 95% CI 5.82-7.46; trauma, aHR=2.77; 95% CI 2.47-3.11), all-cause hospitalisation (surgical, aHR=2.02; 95% CI 1.95-2.08; trauma, aHR=1.57; 95% CI 1.52-1.62), opioid-related hospitalisation (surgical, aHR=2.49; 95% CI 2.24-2.76; trauma, aHR=1.89; 95% CI 1.73-2.05) and reduced DAOH.

CONCLUSIONS: Among opioid-naive patients who received opioids after surgery or trauma, POU was associated with worse outcomes, including increased mortality. Further investigation is warranted to understand the reasons for continued opioid use beyond 90 days and mechanisms associated with harm.