ObjectivesTo evaluate patient factors associated with post-ureteroscopy opioid prescriptions, provider-level variation in opioid prescribing, and the relationship between opioid-free discharges and ED visits. MethodsThis is a retrospective analysis of a prospective cohort study of adults age 18 years and older who underwent primary ureteroscopy for urinary stones from June 2016 to September 2019 within the Michigan Urological Surgery Improvement Collaborative (MUSIC) Reducing Operative Complications from Kidney Stones (ROCKS) quality improvement initiative. Postoperative opioid prescription trends and variation among practices and surgeons were examined. Multivariable logistic regression models defined risk factors for receipt of opioid prescriptions. The association among opioid prescriptions and postoperative ED visits within 30 days of surgery was assessed among complete case and propensity matched cohorts, matched on all measured characteristics other than opioid receipt. Results13,143 patients underwent ureteroscopy with 157 urologists across 28 practices. Post-ureteroscopy opioid prescriptions and ED visits declined (86% to 39%, P<.001; 10% to 6%, P<.001, respectively). Practice and surgeon-level opioid prescribing varied from 8% to 98%, and 0% to 98%, respectively. Patient-related factors associated with opioid receipt included male, younger age, and history of chronic pain. Procedure-related factors associated with opioid receipt included pre- and post-ureteroscopy ureteral stenting and access sheath use. An opioid-free discharge was not associated with increased odds of an ED visit (OR 0.77, 95% CI 0.62-0.95, P=.014). ConclusionsThere was no increase in ED utilization among those not prescribed an opioid after ureteroscopy, suggesting their routine use may not be necessary in this setting.