Impact of long-term macrolide therapy on the evaluation indicator of outpatient oral antimicrobial use according to the AWaRe classification.

The WHO recently proposed a new indicator for judging the appropriateness of antimicrobial selection according to the AWaRe classification. Although macrolides are often administered for long-term macrolide therapy, the impact of this therapy on the indicator remains unclear. This study examined the impact of this therapy on the indicator for outpatient oral antimicrobial use. Using the JMDC claims database, outpatients who were prescribed an oral antimicrobial at least once between January and December 2022 (n = 2.66 million) were included in the study. The ratio of patient numbers and antimicrobial usage (AMU) were calculated based on age group (<15, 15-64, and ≥65 years) and prescription days (1-15, 16-30, 31-60, 61-90, and ≥91 days), and AMU of each drug was corrected for defined daily doses and classified according to the AWaRe. Patients with chronic airway disease for whom macrolides were prescribed for 91 days and more were defined as long-term macrolide therapy. Macrolides accounted for more than 30 % of total oral AMU in all age groups. In the elderly, 11.2 % of patients were prescribed macrolides for 91 days or more, accounting for 66.4 % of macrolide use. With regard to diseases that were associated with macrolide prescriptions, the percentage of patients prescribed for chronic airway diseases increased as the number of days of prescription increased. These results suggest that the impact of long-term macrolide therapy should be considered when assessing the appropriateness of outpatient oral AMU according to the AWaRe classification.