Background: Opioid use beyond the perioperative period is a recognized adverse outcome, primarily studied in inpatients after complex major surgeries. Our goals are to determine the risk after ambulatory surgery and identify risk factors associated with long-term opioid prescriptions.

Methods: Our ambulatory surgery cohort included 1,393,332 veterans from October 1, 2011, to September 30, 2018 (fiscal year [FY] 12-18). Data included age, sex, race, rurality of patient residence and facility, body mass index, tobacco use, Charlson Comorbidity Index, psychiatric disorder, pain score at surgery, substance use, and medications (benzodiazepine, tricyclics and/or selective serotonin reuptake inhibitor and opioids in the 12 months previous).

Results: In aggregate, 9.6% had 1 or more prescriptions in the 90-180 days after surgery ("Persistent prescription[s]") and 1.8% had more than 180 days of opioids in the 31-366 days after surgery ("Chronic prescriptions"). For persistent prescription(s), trends over time decreased from 12.5% in FY12 to 7.1% by FY18 (P < .001). Similarly chronic prescriptions decreased from 2.9% in FY12 to 0.8% in FY18 (P < .001). The strongest independent association for persistent and chronic prescriptions after ambulatory surgery was previous prescription opioids, with 2.8 times increased risk for persistent prescriptions (adjusted odds ratio, 2.8; 95% confidence interval, 2.8-2.9; P < .001) and 3.3 times increased risk for chronic opioid prescriptions (adjusted odds ratio, 3.3; 95% confidence interval, 3.2-3.4; P < .001).

Conclusions: Rates of persistent and chronic opioid prescriptions after ambulatory surgery in the Veterans Health Administration are small and decreasing over time. Providers and patients should have informed discussions regarding risks of opioid postoperative pain management strategies.