RESUMO
BACKGROUND: Severe injuries in child-care institutions are an important social issue. However, no reports on this matter have been made in Japan. This study examined trends in severe injuries at child-care institutions, including the impact of the coronavirus disease 2019 (COVID-19) pandemic. METHODS: We conducted a serial cross-sectional study and interrupted time-series (ITS) analysis with a linear regression model to assess trends in the incidence rate of severe injuries using Japanese national open data between January or April 2017 and December 2021. Participants were individuals utilizing legislated types child-care institutions. The outcomes were annual and monthly incidence rates of severe injuries in legislated types child-care institutions. RESULTS: The number of legislated types child-care institutions increased from 32,793 facilities in 2017 to 38,666 facilities in 2021, and the number of participants rose from 2,802,228 in 2017 to 3,059,734 in 2021. The annual incidence rate of severe injuries in 2021 was 58.3 cases per 100,000 person-years, which is twofold higher than that in 2017. The ITS for the monthly incidence rate demonstrated an increasing trend before the COVID-19 pandemic. CONCLUSIONS: Before the COVID-19 pandemic, the monthly incidence rate of severe injuries in legislated types child-care institutions increased. The annual incidence rate in Japan may have also increased during the observation period.