Changes in the Appropriateness of US Outpatient Antibiotic Prescribing after the Coronavirus Disease 2019 Outbreak: an Interrupted Time Series Analysis of 2016–2021 Data

Background No national study has evaluated changes in the appropriateness of US outpatient antibiotic prescribing across all conditions and age groups after the coronavirus disease 2019 (COVID-19) outbreak in March 2020.Methods This was an interrupted time series analysis of Optum's de-identified Clinformatics Data Mart Database, a national commercial and Medicare Advantage claims database. Analyses included prescriptions for antibiotics dispensed to children and adults enrolled during each month during 2017-2021. For each prescription, we applied our previously developed antibiotic appropriateness classification scheme to International Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes on medical claims occurring on or during the 3 days prior to dispensing. Outcomes included the monthly proportion of antibiotic prescriptions that were inappropriate and the monthly proportion of enrollees with >= 1 inappropriate prescription. Using segmented regression models, we assessed for level and slope changes in outcomes in March 2020.Results Analyses included 37 566 581 enrollees, of whom 19 154 059 (51.0%) were female. The proportion of enrollees with >= 1 inappropriate prescription decreased in March 2020 (level decrease: -0.80 percentage points [95% confidence interval {CI}, -1.09% to -.51%]) and subsequently increased (slope increase: 0.02 percentage points per month [95% CI, .01%-.03%]), partly because overall antibiotic dispensing rebounded and partly because the proportion of antibiotic prescriptions that were inappropriate increased (slope increase: 0.11 percentage points per month [95% CI, .04%-.18%]). In December 2021, the proportion of enrollees with >= 1 inappropriate prescription equaled the corresponding proportion in December 2019.Conclusions Despite an initial decline, the proportion of enrollees exposed to inappropriate antibiotics returned to baseline levels by December 2021. Findings underscore the continued importance of outpatient antibiotic stewardship initiatives. In this analysis of commercial and Medicare Advantage claims, the proportion of US enrollees with >= 1 inappropriate antibiotic prescription declined after the COVID-19 outbreak but rebounded to prepandemic levels by December 2021, underscoring the continued importance of antibiotic stewardship initiatives.