Trends in inpatient antimicrobial consumption using days of therapy and days of antibiotic spectrum coverage: A nationwide claims database study in Japan

Abstract

Introduction: Days of antibiotic spectrum coverage (DASC), a novel metric for both antimicrobial volume and spectrum, was proposed to measure inpatient antimicrobial consumption in 2022. The DASC may better reflect efforts toward antimicrobial stewardship; however, no previous study has described the distribution of trends in DASC in hospitals or the association between the trend in DASC and days of therapy (DOT). This study assessed trends in antimicrobial consumption for inpatients at acute care hospitals in Japan using the DOT and DASC.

Methods: This retrospective observational study used the nationwide administrative inpatient claims database of Japanese acute care hospitals between 2014 and 2018. The prescriptions of all antibiotics were identified to calculate DOT/1000 patient-days, DASC/1000 patient-days, and DASC/DOT. We described the five-year trend in these metrics and examined the association between the trends in DOT and DASC.

Results: In total, 26,301,685 admissions from 634 hospitals were included. The DOT/1000 patient-days and DASC/1000 patient-days increased significantly by 6.1% and 5.6%, respectively. The DASC/DOT ratio did not change significantly (P = 0.35). Moreover, there was little correlation between DOT/1000 patient-days and DASC/DOT (R² = 0.01). There was also little correlation between the five-year changes in DOT/1000 patient-days and those in DASC/DOT (R² = 0.02).

Conclusions: It may be difficult to assess trends in the antibiotic spectrum using DASC alone. However, the combination of DOT as a quantity indicator and DASC/DOT as a spectrum indicator may allow for a more appropriate evaluation of stewardship efforts.

Keywords: Antibiotic spectrum coverage score; Antimicrobial consumption; Antimicrobial stewardship; Days of antimicrobial coverage; Days of therapy.