BackgroundPrevious studies have reported high levels of inappropriate ambulatory antibiotic prescribing in the United States. This population-based cohort study examines temporal trends in appropriateness of ambulatory antibiotic prescribing in South Carolina.MethodsAggregated pharmacy claims data for oral antibiotic prescriptions among South Carolina residents < 65 years old were matched with primary diagnosis codes from medical claims within 14 days of the pharmacy claim from 2012–2017. Appropriateness of antibiotics was defined as maybe indicated or not indicated based on diagnosis codes. Chi-square tests were used to examine overall temporal trend in appropriateness and the trends across age group and gender.ResultsDuring the 6-year period, 3,133,379 prescriptions were identified. Overall, 25.6% of antibiotic prescriptions filled were not indicated. This decreased from 27.9% in 2012 to 22.7% in 2017 (p < 0.001). The most common not indicated conditions were viral upper respiratory infections (39.1%), bronchitis (26.7%), and serous otitis (10.9%). The most common maybe indicated conditions were bacterial otitis (27.5%), acute bacterial tonsillitis (24.8%), and sinusitis (23.6%). While females filled more antibiotic prescriptions, they were less likely than males to have a not indicated condition (24.7% vs. 27.1%, p < 0.001). Prescribing for not indicated conditions was more likely in adults aged 40–64 (33.7%) than those aged 18–39 (23.5%) and < 18 (24.2%).ConclusionThe observed decline in inappropriate ambulatory antibiotic prescribing from 2012 to 2017 in South Carolina represents welcomed news. Further improvements in ambulatory antibiotic stewardship efforts are needed particularly in men ≥ 40 years old with acute respiratory infections.DisclosuresJulie Ann Justo, PharmD, MS, BCPS-AQ ID, bioMerieux (Speaker’s Bureau)TRC Healthcare (Speaker’s Bureau)