Fifteen-year secular changes in the care and outcomes of patients with out-of-hospital cardiac arrest in Japan: a nationwide, population-based study

Abstract Aims Countries have implemented initiatives to improve the outcomes of patients with out-of-hospital cardiac arrest (OHCA). However, secular changes in care and outcomes at the national level have not been extensively investigated. This study aimed to determine 15-year secular changes in the outcomes of such patients in Japan. Methods and results Using population-based data of patients with OHCA, covering all populations in Japan (2005–19), patients for whom resuscitation was attempted were identified. The primary outcome was a favourable neurological outcome (Cerebral Performance Category 1 or 2: sufficient cerebral function for independent activities of daily life and work in a sheltered environment). Secular changes in outcomes were determined using a mixed-level multivariate logistic regression analysis. Overall, 1 764 440 patients (42.4% women; median age, 78 years) were examined. The incidence, median age, and proportion of patients who received bystander cardiopulmonary resuscitation (CPR) and dispatcher instructions for resuscitation increased significantly during the study period (P < 0.001). A significant trend was noted toward improved outcomes over time (P for trend < 0.001); favourable neurological outcome proportions 1 month after arrest increased from 1.7–3.0% (odds ratio, 1.03 per 1-incremental year). A remarkable increase was noted in favourable neurological outcomes in younger patients and patients with initial shockable cardiac rhythm, while improvement varied among prefectures. Conclusion In Japan, collaborative efforts have yielded commendable achievements in the care and outcomes of patients with OHCA over 15 years through to 2019, while the improvement depended on patient characteristics. Further initiatives are needed to improve OHCA outcomes.