Trends in Antibiotic Use for Kidney Stone Patients Discharged from United States Emergency Departments

Introduction: Patients with ureteral stones and concurrent urinary tract infections (UTIs) are at risk of developing sepsis and warrant urgent urinary drainage. However, in the absence of overt signs of infection, antibiotics are unlikely to be beneficial. Patients without infection may be discharged from the emergency department (ED) with unnecessary empiric antibiotics, promoting antimicrobial resistance. This research evaluated trends in antibiotic use for kidney stone patients discharged from EDs in the United States from 2015 to 2022. Methods: National Hospital Ambulatory Medical Care Survey data were scaled to national estimates. Concurrent infection was defined by International Classification of Diseases, Tenth Revision, codes for sepsis or UTI. Antibiotic use trends were estimated via logistic regressions on the date of the encounter; an interaction term accounted for an observed inflection point in antibiotic use in 2020. Results: A total of 9,651,950 patients presented with kidney stones to the ED and were discharged the same day, including 12% with ICD-coded concurrent infection. Seventeen percent received a prescription at discharge. Among patients without infection, 18% received antibiotics. From 2015 to 2019, antibiotic use declined from 28% to 16% of encounters (annual odds ratio OR = 0.82, p = 0.006). However, this trend ended in 2020, and antibiotics were given in 32% of encounters by 2022. Antibiotic use was more common in females (OR = 2.24), those aged 65–74 (OR = 5.24), and patients with concurrent infection (OR = 11.15), all p < 0.01. Among those receiving antibiotics, the most common classes were cephalosporins (49%), fluoroquinolones (32%), and sulfonamides (12%). Conclusions: Antibiotics are commonly given to kidney stone patients, even in the absence of infection, and many patients with concurrent infection are discharged from the ED, rather than urgently drained or admitted for observation. These data suggest that antibiotics are frequently overused in the care of kidney stone patients in the ED, and the COVID-19 pandemic may have set back national efforts in antibiotic stewardship.