Decreases and Pronounced Geographic Variability in Antibiotic Prescribing in Medicaid

Background Antibiotic resistance is a persistent and growing concern. Our objective was to analyze antibiotic prescribing data in the United States (US) to identify trends in the Medical Expenditure Panel System (MEPS) and any state-level disparities to Medicaid patients. Methods We obtained total MEPS prescriptions for eight antibiotics from 2013 to 2020. We extracted prescribing rates per 1,000 Medicaid enrollees for two years, 2018 and 2019, for four broad spectrum (azithromycin, ciprofloxacin, levofloxacin, and moxifloxacin) and four narrow spectrum (amoxicillin, cephalexin, doxycycline, and trimethoprim/sulfamethoxazole) antibiotics. Results Antibiotics in MEPS decreased from 2013 to 2020 by −38.7% with a larger decline for broad (−53.7%) than narrow spectrum (−23.5%). Antibiotic prescriptions decreased from 2018 to 2019 and by −6.7% when correcting for the number of Medicaid enrollees. Amoxicillin was the predominant antibiotic followed by azithromycin, cephalexin, trimethoprim/sulfamethoxazole, doxycycline, ciprofloxacin, levofloxacin, and moxifloxacin. Substantial geographic variation in antibiotic prescribing existed with 2.8-fold between the highest (Kentucky = 855/1,000) and lowest (Oregon = 299) states. The South prescribed 52.2% more antibiotics (580/1,000) than the West (381/1,000). There were significant correlations across states in antibiotic prescribing. Conclusions & Relevance This study identified sizable disparities by geography in prescribing rates of eight antibiotics with over three-fold state level differences. The South had the highest prescribing rates among all the regions. Areas with high antibiotic prescribing rates, particularly for outpatients, may benefit from programs to reduce potentially unnecessary prescribing. Further analysis of state level Medicaid or prescribing policies is needed to identify reasons for the variation in prescribing rates.