Cost of inappropriate antimicrobial use for upper respiratory infection in Japan

BACKGROUND: Antibiotics are often prescribed inappropriately to patients with upper respiratory infection (URI) in ambulatory care settings; however, the economic burden of such prescription has not been quantitatively assessed. Here, we aimed to evaluate the additional cost of antimicrobial prescription for URI at the population level in Japan. METHODS: We conducted a retrospective observational survey using longitudinal claims data between 2013 and 2016 obtained from JMDC Claims Database, which contains data from 5·1 million corporate employees and family members under the age of 65 years. Appropriateness of antibiotic prescription was assessed by a panel of six infectious disease physicians according to ICD-10 code in JMDC Claims Database. Total additional cost of antibiotic prescription for URI at the national level was estimated by weighting of age-structured population data. RESULTS: The annual additional cost of inappropriate antibiotic prescription for URI was estimated at 423·6 (95% CI: 416·8–430·5) million USD in 2013, 340·9 (95% CI: 335·7–346·2) million USD in 2014, 349·9 (95% CI: 344·5–355·3) million USD in 2015, and 297·1 (95% CI: 292·4–301·9) million USD in 2016. Three classes of broad-spectrum oral antibiotics (third-generation cephalosporins, macrolides, and fluoroquinolones) accounted for > 90% of the total additional cost. CONCLUSIONS: Although a decreasing trend was observed, annual additional costs of inappropriate antibiotic prescriptions for URI could be a substantial economic burden in Japan. Appropriately prescribing broad-spectrum oral antibiotics might be an important issue to reduce unnecessary medical costs in Japanese ambulatory care.