Epidemiology of Antimicrobial Use among Nursing Homes in Japan, 2016: a Pilot Study

Antimicrobial resistance is an emerging problem in both acute care hospitals and nursing homes. From January to December 2016, we conducted a pilot, descriptive epidemiological study to examine antimicrobial use (AMU) among 6 nursing homes in Tokyo, Japan. AMU was extracted from prescription data of a pharmacy that received all prescriptions from the 6 nursing homes. To standardize the comparison of drug usage, AMU was measured using the defined daily dose (DDD) and estimated as DDDs/1,000 resident-days. The overall AMU was 15.3/1,000 resident-days, including oral antimicrobials (15.2/1,000 resident-days [99.3%]). The most frequently prescribed oral-antimicrobials was macrolides (5.8/1,000 resident-days [38.2%]) and quinolones (4.2/1,000 resident-days [27.6%]). Oral macrolides and quinolones were thought to be a convenience in prescription among nursing homes with resource limiting due to smaller defined the number of daily doses compared to penicillins and cephalosporins. In addition, multicenter studies that include resident-specific data (demographics and diagnosis) and focus on the purpose of antimicrobials (treatment or prevention) are needed to evaluate the appropriateness of antimicrobials.