Antimicrobial prescribing for upper respiratory infections and its effect on return visits

Background and Objectives: Antibiotic resistance is a growing problem that complicates the treatment of various illnesses. This study analyzes Medicaid encounter data to (1) determine antibiotic prescribing rates for common respiratory tract infections in Oregon and (2) assess the effect of receiving an antibiotic at an index visit on whether there was a return visit within 30 days. Methods: Subjects included in this study were Medicaid patients in Oregon between 2001-2003 who were enrolled in Medicaid for a full year and were diagnosed with an upper respiratory tract infection, including bronchitis, sinusitis, acute otitis media (AOM), pharyngitis, and upper respiratory infections (URIs). Claims data were analyzed to determine receipt of an antibiotic within 3 days of the initial visit and if there was a return visit within 30 days. Results: During 2001-2003, the proportion of patients receiving antibiotics for bronchitis and sinusitis decreased, from 70% to 61%, and from 78% to 74%, respectively, while antibiotic prescribing for AOM, URI, and pharyngitis changed little. After controlling for age, gender, race/ethnicity, Medicaid plan type, and location, we determined that patients who had received antibiotics during the index visit for AOM, URI, and pharyngitis were more likely to return with a respiratory tract infection during the subsequent 30 days than patients who did not receive antibiotics. Conclusions: Antibiotic prescribing among Medicaid patients in Oregon has decreased. Receiving an antibiotic does not decrease the rate of subsequent return visits.