Trends in Life-Sustaining Treatment Decisions and Their Implementation: An Interrupted Time Series Analysis

Background/Aims: Since enforcement of the Life-Sustaining Treatment (LST) Decisions Act, a pilot project for medical insurance reimbursement related to LST decisions and their implementation began in February 2018. This pilot project transitioned into a full-scale project in January 2022 that continues to this day.Methods: We observed trend changes in LST decisions and their implementation by performing an interrupted time series analysis of data from the Health Insurance Review and Assessment Service from February 2018 to September 2023. We focused on two events: coronavirus disease 2019 (COVID-19) and the transition to a full-scale project.Results: Our interrupted time-series analysis used the onset of COVID-19 (January 2020) as its reference point. The slopes of most codes for LST decisions and their implementation decreased following the onset of COVID-19. When divided by hospital class, all codes in hospitals, nursing hospitals, and oriental medicine hospitals showed immediate increases before and after the COVID-19 outbreak. A separate interrupted time series analysis was conducted using the transition to a full-scale project (January 2022) as the reference point. While no immediate effects were observed before or after transitioning to full-scale projects, in the institution-specific data, the slopes of all codes in general, nursing, and oriental medicine hospitals increased.Conclusions: Our results reveal that COVID-19 and the transition to a full-scale project have significantly impacted LST decisions and their implementation. These findings can be used to evaluate and improve reimbursement programs.