Regional variations in early and late survival after out-of-hospital cardiac arrest.

BACKGROUND: While prior studies highlight regional variations in out-of-hospital cardiac arrest (OHCA) survival, the underlying reasons remain unknown. We sought to characterize regional variations early and later survival to hospital discharge after OHCA.
METHODS: We studied adult, non-traumatic OHCA treated by 10 regional sites of the Resuscitation Outcomes Consortium (ROC) during 12/01/2005-6/30/2007. We compared (1) early survival (up to one calendar day after arrest) and (2) later conditional survival to hospital discharge (early survivors progressing to eventual hospital discharge) between ROC regional sites.
RESULTS: Among 3763 VF/VT with complete covariates, site unadjusted early survival varied from 11.3 to 54.3%, and site unadjusted later survival varied from 33.3 to 70.5%. Compared with the largest site, adjusted VF/VT survival varied across sites: early survival OR 0.33 (95% CI: 0.17, 0.65) to 2.87 (2.20, 3.73), overall site variation p<0.001; later survival OR 0.29 (0.14, 0.59) to 1.21 (0.73, 2.00), p<0.001. Among 10,879 non-VF/VT with complete covariates, site unadjusted early survival varied from 6.6 to 14.3%, and site unadjusted later survival varied from 4.5 to 39.6%. Compared with the largest site, adjusted non-VF/VT survival varied across sites: early survival OR 1.02 (0.63, 1.64) to 2.43 (1.91, 3.12), p<0.001; later survival OR 0.11 (0.01, 0.82) to 1.56 (0.90, 2.70), p=0.02.
CONCLUSIONS: In this prospective multicenter North American series, there were regional disparities in early and later survival after OHCA, suggesting that there are underlying regional differences in out-of-hospital and post-arrest care beyond traditional Utstein predictors. Community efforts to improve OHCA survival must address both out-of-hospital and in-hospital care.