Discharge of postoperative patients with an opioid prescription is associated with increased persistent opioid use, healthcare expenditures and mortality: a retrospective cohort study.

BACKGROUND: The risk factors for persistent opioid use after surgical discharge and the association between opioid prescription at discharge and postoperative emergency department visits, readmission, and mortality are unclear. METHODS: This population-based retrospective cohort study involved opioid-naive patients who underwent surgical procedures from January 1, 2000 to November 30, 2020. The data source was Hong Kong Hospital Authority Clinical Management System electronic health record. The primary outcome was the incidence of new persistent opioid use. Other study outcomes included 30-day emergency department visits, 30-day readmission, and 30-day all-cause mortality. Multivariable logistic regression models were used to estimate the association between opioid prescription at discharge and persistent opioid use, emergency department visits, readmission, and all-cause mortality. RESULTS: Over a median follow-up of 1 month with 36 104 person-years, 438 128 patients (opioid prescription: 32 932, no opioid prescription: 405 196) who underwent surgical procedures were analysed, of whom 15 112 (3.45%) had persistent opioid use after discharge. Prescribing opioids on discharge was associated with increased risks of developing persistent opioid use (odds ratio [OR]: 2.30, 95% confidence interval [CI]: 2.19-2.40, P<0.001), 30-day emergency department visits (OR: 1.28, 95% CI: 1.23-1.33, P<0.001), 30-day readmission (OR: 1.17, 95% CI: 1.13-1.20, P<0.001), and 30-day all-cause mortality (OR: 1.68, 95% CI: 1.53-1.86, P<0.001). CONCLUSIONS: In this large cohort of patients undergoing surgery, an opioid prescription on discharge was associated with a higher chance of persistent opioid use and increased risks of postoperative emergency department visits, readmission, and mortality. Minimising opioid prescriptions on discharge could improve perioperative patient outcomes.