Differences by patient race in guideline concordant outpatient antibiotic use in adult patients in Michigan

Purpose: To determine if there are significant differences in the rate of guideline concordant antibiotic use by race in adult patients in the state of Michigan. Methods: Using the Collaboration to Harmonize Antimicrobial Registry Measures (CHARM) database, outpatient prescriptions from 6 health systems throughout the state of Michigan in 2021 were reviewed, and the 5 infectious disease diagnoses with the most antibiotic prescriptions were identified. The 2 most common races amongst patients were identified, and the differences in rates of guideline concordance were compared between them. Results: A total of 62,070 outpatient prescriptions were identified for the 2 most common races, White and Black or African American. Of those, 43,519 outpatient prescriptions were identified for the top 5 infectious diagnoses, acute cystitis, acute sinusitis, acute pharyngitis, cellulitis, and otitis media. Antimicrobial choice concordance was higher in patients who are White (71.6% vs. 68.5%; p<0.01), while antibiotic dosing concordance was higher in patients who are Black or African American (65.9% vs 68.4%; p=0.02). Differences in antimicrobial choice concordance was primary driven by acute cystitis with more patients who are Black or African American receiving doxycycline (1.1 % vs 6.0%; p<0.01). Differences in antimicrobial dose concordance was primary driven by acute pharyngitis with fewer patients who are White receiving concordant doses of amoxicillin (45.5 % vs 64.6%; p<0.01). Conclusion: Differences in rates of antibiotic choice and dosing concordance were seen between patients who are White and Black or African American. Further studies investigating the clinical significance of these differences are warranted. IRB approval: This study was evaluated by the local Institutional Review Board and determined to be exempt because it did not involve human subjects research.