Financial incentives for infection prevention and antimicrobial stewardship to reduce antibiotic use: Japan's nationwide observational study

The Japanese government introduced financial incentives to reduce nationwide antibiotic use in hospital settings.This study aimed to determine whether the nationwide financial incentives for creating infection prevention and control (IPC) teams introduced in 2012 and antimicrobial stewardship (ASP) teams introduced in 2018 were associated with changes in antibiotic use and health resource utilization at a national level.We conducted time-series analyses and a difference-in-differences study consisting of 3,057,517 inpatients with infectious diseases from 472 medical facilities during fiscal years 2011-2018 using a nationally representative inpatient database in Japan. The primary outcome was the days of therapy (DOT) of antibiotic use per 100 patient-days (PDs). The secondary outcomes consisted of types of antibiotic used, health resource utilization, and mortality.A total of 5,201,304 financial incentives were observed during 2012-2018, which resulted in a total of 12.1 billion JPY (≈110 million USD). Time-series analyses found decreasing trends in total antibiotic use (79.3-72.5 DOTs/100 PDs (8.6% reduction)) and carbapenem use (9.0-7.0 DOTs/100 PDs (7.8% reduction)) from 2011 to 2018 without adversely affecting other healthcare outcomes (e.g., mortality). In the difference-in-differences analyses, we did not observe meaningful changes in total antibiotic use between the incentivized and unincentivized hospitals for ASP teams, except for the northern part of Japan. No dose-response relationships were observed between the amount of financial incentives and reductions in antibiotic use during 2011-2019.Further research and efforts are needed to accelerate antimicrobial stewardship in hospital settings in Japan.