Prevalence of antimicrobial use and active healthcare-associated infections in acute care hospitals: a multicentre prevalence survey in Japan

OBJECTIVE: To determine the prevalence of antimicrobial drug use and active healthcare-associated infections (HAIs) and to evaluate the appropriateness of antimicrobial therapy in acute care hospitals in Japan. DESIGN: A prospective multicentre cross-sectional study. PARTICIPANTS: All hospitalised patients on a survey day. MAIN OUTCOME MEASURES: The primary outcome was the proportion of patients receiving any antimicrobial agents. The secondary outcome was the proportion of patients with active HAIs. The reasons for antimicrobial drug use and appropriateness of antibiotic therapy were also investigated. RESULTS: Eight hundred twenty eligible patients were identified. The median patient age was 70 years (IQR 55–80); 380 (46.3%) were women, 150 (18.3%) had diabetes mellitus and 107 (13.1%) were immunosuppressive medication users. The proportion of patients receiving any antimicrobial drugs was 33.5% (95% CI 30.3% to 36.8%). The proportion of patients with active HAIs was 7.4% (95% CI 5.6% to 9.2%). A total of 327 antimicrobial drugs were used at the time of the survey. Of those, 163 (49.8%), 101 (30.9%) and 46 (14.1%) were used for infection treatment, surgical prophylaxis and medical prophylaxis, respectively. The most commonly used antimicrobial drugs for treatment were ceftriaxone (n=25, 15.3%), followed by piperacillin–tazobactam (n=22, 13.5%) and cefmetazole (n=13, 8.0%). In the 163 antimicrobial drugs used for infection treatment, 62 (38.0%) were judged to be inappropriately used. CONCLUSIONS: The prevalence of antimicrobial use and active HAIs and the appropriateness of antimicrobial therapy in Japan were similar to those of other developed countries. A strategy to improve the appropriateness of antimicrobial therapy provided to hospitalised patients is needed. TRIAL REGISTRATION NUMBER: UMIN000033568