Pharmacoepidemiology of Antibiotic Prescribing Among 135,000 Adult Outpatient Encounters in Northeast Ohio

Abstract Background Nearly 154 million ambulatory visits in the United States result in an outpatient antibiotic prescription (OAP) annually, 30% of which are unnecessary. Remaining prescriptions may benefit from improved antibiotic selection. At our institution, a quarterly OAP report associated with 4 common encounter diagnoses was developed. The objectives of this study were to assess OAP rate for each diagnosis, and to assess the rate of guideline-concordant selection when an OAP was issued. Methods OAP report from January 2016 – March 2017 was queried to conduct a retrospective pharmacoepidemiology study including data from 106 outpatient sites, 33 care institutes, and 1400 providers in Northeast Ohio. The report aggregated OAPs for all office and telephone encounters with a diagnosis code for otitis media, pharyngitis, sinusitis, or urinary tract infection. For each diagnosis, encounters that resulted in an OAP were then categorized as guideline-concordant or -discordant based on the antibiotic selected and includes consideration of labeled penicillin allergy and consensus guideline recommendations (Figure 1). All data were filterable to the practice site, care institute, or prescriber level. Results A total of 135,177 patient encounters were captured during the study period (9766 otitis media, 39570 pharyngitis, 60940 sinusitis, 24901 urinary tract infection). Mean patient age was 50 (±15) years. At least 1 OAP was issued in 8444 (86%) otitis media, 16143 (41%) pharyngitis, 46343 (76%) sinusitis, and 15464 (62%) urinary tract infection encounters. For encounters in which an OAP was issued, the rate of guideline-concordant antibiotic selection by diagnosis was 46% for otitis media, 58% for pharyngitis, 64% for sinusitis, and 50% for urinary tract infection. Antibiotic selection for pharyngitis and sinusitis during Q1 2017 are detailed in Figures 2 and 3, respectively. Conclusion Audit of outpatient prescribing data revealed a high rate of OAP issuance for these four common diagnoses. The use of guideline-discordant antibiotics was also prevalent and commonly consisted of macrolides, fluoroquinolones, tetracyclines, and cephalosporins. These data provide an important baseline that underscores the need for outpatient stewardship and facilitates targeted prospective interventions. Disclosures All authors: No reported disclosures.