The incidence of persistent postoperative opioid use among U.S. veterans: A national study to identify risk factors.

Objective: To calculate the incidence and identify the predictors of persistent postoperative opioid use at different postoperative days.

Background Data: A subset of surgical patients continues to use long-term opioids. The importance of the risk factors at different postoperative days is not known.

Design: A historical cohort.

Setting: Postoperative period.

Patients: Opioid-naive U.S. veterans.

Interventions: The surgical group had any one of 19 common invasive procedures. The control group is a 10% random sample. Each control was randomly assigned a surgery date.

Measurements: The outcomes were the presence of persistent opioid use as determined by continued filling of prescriptions for opioids on postoperative days 90, 180, 270, and 365.

Main Results: A total of 183,430 distinct surgical cases and 1,318,894 controls were identified. 1.0% of the surgical patients were using opioids at 90 days, 0.6% at 180 days, 0.4% at 270 days, and 0.1% at 365 days after the surgery. Surgery was strongly associated with postoperative persistent opioid use at day 90 (OR 3.67, 95% CI, 3.43-3.94, p < 0.001), at day 180 (OR 2.85, 2.67-3.12, p < 0.001), at day 270 (OR 2.63, 2.38-2.91, p < 0.001) and at day 365 (OR 2.11, 1.77-2.51, p < 0.001) compared to non-surgical controls. In risk factor analysis, being male and single were associated with persistent opioid use at earlier time points (90 and 180 days), while hepatitis C and preoperative benzodiazepine use were associated with persistent opioid use at later time points (270 and 365 days).

Conclusions: Many surgeries or invasive procedures are associated with an increased risk of persistent postoperative opioid use. The postoperative period is dynamic and the risk factors change with time.