To evaluate the proportion of US Medicare patients undergoing ureteroscopy (URS) for kidney stone management at risk for adverse outcomes and analyze the association between risk factors and adverse events.

Data from Medicare patients aged ≥65 who underwent URS between 2019 and 2023 were analyzed. Nine risk factors were examined for their prevalence and association with sepsis and intensive care unit (ICU) admission within 30 days, extended length of stay (LOS) during the index procedure, and death within 90 days.

Among 290,610 Medicare patients who underwent URS, 94.4% had ≥1 (n = 274,396) and 76.3% had ≥2 risk factors. The proportion of patients with each risk factor was: age over 70 (64.6%), preoperative stent (59.4%), female (46.4%), urinary tract infection within 3 months (39.1%), diabetes (33.0%), history of sepsis (17.3%), multiple urinary tract infections within 6 months (13.1%), Charlson Comorbidity Index score of ≥7 (10.2%), and ischemic heart disease (2.9%). Patients with risk factors experienced a higher incidence of adverse outcomes. Notably, among patients with sepsis history, the incidence of sepsis, ICU admission within 30 days, and death within 90 days were 30.3%, 2.5%, and 0.86%, respectively, versus, 2.2%, 0.80%, and 0.18% without sepsis history (all P <.001). Median LOS was 5 days among patients with sepsis history versus 3 days without (P <.001).

Most URS Medicare patients had risk factors. Those with risk factors were more likely to experience sepsis, ICU admission, prolonged hospital LOS, and death. These findings underscore the need for targeted prevention and careful management for high-risk URS patients.