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

BACKGROUND

Little 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.

METHODS

Using 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.

RESULTS

The 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.

CONCLUSIONS

We found nationwide and regional improvement of favourable neurological outcomes from OHCA of medical origin with persistent regional variation.