Assignments of antibiotic spectrum coverage scores of antibiotic agents approved in Japan: Utilization of the days of antibiotic spectrum coverage

Integrating the automated collection of antimicrobial use metrics into national surveillance systems is vital for antimicrobial stewardship evaluation. The days of antibiotic spectrum coverage (DASC) serves as a quantitative metric for assessing de-escalation strategies. A major challenge is that DASC has not yet been integrated into the national surveillance system, partly owing to the omission of commonly used antibiotics in Japan in the initially developed antibiotic spectrum coverage (ASC) scores. This study aimed to establish ASC scores for antibiotics approved in Japan and generate data supporting their integration into the national surveillance system. Antibiotics approved in Japan that had not been assigned ASC scores in the prior study were identified. Their antimicrobial activity was assessed against 16 organism categories using the same methodology as the original study. We analyzed the correlation between the Access, Watch, Reserve (AWaRe) classification and ASC scores for antibiotics approved in Japan. The ASC scores had a range of 3–16, with a median of seven. The AWaRe classification was slightly correlated with ASC scores (Spearman's ρ = 0.234). Our findings highlight the significance of employing diverse antimicrobial use metrics for comprehensively evaluating antimicrobial stewardship. The results of this study will support stakeholders in implementing ASC scores into the national surveillance system.