(1537) Effect of a Rapid Response System on the Incidence of In-Hospital Cardiac Arrest

Introduction: The Rapid Response System (RRS) is based on the understanding that many sudden changes exhibit early warning signs. It is designed to prevent fatal outcomes by recognizing abnormal vital signs early and intervening promptly. In Japan, the 2022 revision of medical fees prompted the introduction of RRS in many hospitals. Our hospital also introduced RRS in March 2023. The aim of this study was to assess the effect of the implementation of a rapid response system on the incidence of in-hospital cardiac arrest (IHCA).

Methods: This was a retrospective observational study conducted from January 2019 to December 2023. We analyzed data on all consecutive patients in the general wards of Osaka General Medical Center during the study period. The primary outcome of this study was the incidence of IHCA, defined as the number of IHCAs in the general ward per 10,000 ward bed days, including DNAR patients, each month. To assess the effect of the RRS, we used a Bayesian structural time series model, splitting the observation period into two periods: before (January 2019 - February 2023) and after (March 2023 - December 2023) the introduction of the RRS. To adjust for the effects of seasonality, the month of occurrence was included in the model as a covariate.

Results: This study included 44,232 patients. The predicted monthly incidence of IHCA after the introduction of RRS was 4.5 in the absence of RRS, compared with 1.4 in the actual measurement. This confirmed a reduction of 3.1 (95% confidence interval: -5.0 to -1.2). As for the cumulative effect, the actual cumulative value was 13.7, compared with a predicted cumulative value of 44.6 in the absence of the RRS. This confirmed a cumulative reduction of 30.9 (95% confidence interval: -50.0 to -11.7). The introduction of RRS reduced the incidence of IHCA by 67% (95% confidence interval: -79% to -46%, p = 0.003).

Conclusions: The implementation of the RRS contributed to a significant reduction in the incidence of IHCA.