Nationwide and regional trends in survival from out-of-hospital cardiac arrest in Japan: A 10-year cohort study from 2005 to 2014

Abstract

BackgroundLittle is known about the most recent nationwide and regional trends in out-of-hospital cardiac arrest (OHCA) outcome. We therefore sought to investigate the recent nationwide and regional trends in OHCA outcome in Japan. MethodsUsing nationwide, population-based OHCA registry in Japan, we evaluated outcome from emergency-medical-services resuscitated OHCA of medical origin between 2005 and 2014. A total of 861,756 OHCA patients of medical origin were eligible for our analyses. We assessed annual nationwide OHCA outcome and regional trend among seven representative regions between two periods, 2005–2009 and 2010–2014. The primary outcome was one-month survival with favourable neurological outcome, defined as Cerebral Performance Category scale of 1 or 2. ResultsThe nationwide 1-month survival with favourable neurological outcome increased from 1.1% to 2.3% in OHCA of medical origin. Using multivariable analysis, favourable neurological outcome in 2014 significantly increased (adjusted OR, 2.81; 95% CI, 2.57–3.07), compared with that in 2005. Among seven regions, favourable neurological outcome from OHCA of medical origin varied in the 2005–2009 period (1.3%–2.2%) and 2010–2014 period (1.7%–2.8%). Using multivariable analysis, these disparities persisted in 2005–2009 (the range of adjusted OR, 0.88–1.85) and 2010–2014 (the range of adjusted OR, 1.00–1.83) periods, using Kanto region as the reference. All regions showed increase in favourable neurological outcome during 2010–2014 period (the range of adjusted OR, 1.44–1.82), using 2005–2009 period as the reference. ConclusionsWe found nationwide and regional improvement of favourable neurological outcomes from OHCA of medical origin with persistent regional variation.