To compare the factors associated with survival after out-of-hospital cardiac arrests (OHCAs) among three time-distance areas (defined as interquartile range of time for emergency medical services response to patient\'s side).
From a nationwide, prospectively collected data on 716,608 OHCAs between 2007 and 2012, this study analyzed 193,914 bystander-witnessed OHCAs without pre-hospital physician involvement.
Overall neurologically favourable 1-month survival rates were 7.4%, 4.1% and 1.7% for close, intermediate and remote areas, respectively. We classified BCPR by type (compression-only vs. conventional) and by dispatcher-assisted CPR (DA-CPR) (with vs. without); the effects on time-distance area survival were analyzed by BCPR classification. Association of each BCPR classification with survival was affected by time-distance area and arrest aetiology (p<0.05). The survival rates in the remote area were much higher with conventional BCPR than with compression-only BCPR (odds ratio; 95% confidence interval, 1.26; 1.05-1.51) and with BCPR without DA-CPR than with BCPR with DA-CPR (1.54; 1.29-1.82). Accordingly, we classified BCPR into five groups (no BCPR, compression-only with DA-CPR, conventional with DA-CPR, compression-only without DA-CPR, and conventional without DA-CPR) and analyzed for associations with survival, both cardiac and non-cardiac related, in each time-distance area by multivariate logistic regression analysis. In the remote area, conventional BCPR without DA-CPR significantly improved survival after OHCAs of cardiac aetiology, compared with all the other BCPR groups. Other correctable factors associated with survival were short collapse-to-call and call-to-first CPR intervals.
Every effort to recruit trained citizens initiating conventional BCPR should be made in remote time-distance areas.