Temporal trends in out-of-hospital cardiac arrest survival outcomes between two metropolitan communities: Seoul-Osaka resuscitation study

ObjectivesThe objective of this study was to compare the temporal trends in survival after out-of-hospital cardiac arrest (OHCA) between two large metropolitan communities in Asia and evaluate the factors affecting survival after OHCA.DesignA population-based prospective observational study.SettingThe Cardiovascular Disease Surveillance (CAVAS) project in Seoul and the Utstein Osaka Project in Osaka.ParticipantsA total of 36 292 resuscitation-attempted OHCAs with cardiac aetiology from 2006 to 2011 in Seoul and Osaka (11 082 in Seoul and 25 210 in Osaka).Primary outcome measuresThe primary outcome was neurologically favourable survival. Trend analysis and multivariable Poisson regression models were conducted to evaluate the temporal trends in survival of two communities.ResultsDuring the study period, the overall neurologically favourable survival was 2.6% in Seoul and 4.6% in Osaka (p