Regional variability in survival outcomes of out-of-hospital cardiac arrest: the All-Japan Utstein Registry.

OBJECTIVE: There is a paucity of studies on the degree of regional variability in out-of-hospital cardiac arrest (OHCA) outcomes, particularly in neurological outcome. This study aimed to determine whether there is a significant regional variation in survival outcomes of OHCA across Japan.
METHODS: We analyzed a prospective, nation-wide, population-based database (All-Japan Utstein Registry) involving all Japanese individuals who had non-traumatic OHCA resuscitated by emergency responders from January 2005 through December 2010. The primary study endpoint was favourable neurological survival at 1 month, defined as Cerebral Performance Category 1 or 2. We compared unadjusted and multivariable-adjusted rates of the outcome among seven geographic regions.
RESULTS: In the total catchment population of 128 million, there were 539,641 non-traumatic OHCA patients. Unadjusted neurologically favourable survival varied across regions from 1.9% to 3.1% (rate difference, 1.2%; 95%CI, 1.0-1.3%); the Northeast region had a significantly lower rate compared to the Midwest region (unadjusted rate ratio, 0.62; 95%CI, 0.60-0.64). This disparity became larger after adjusting for patient- and prehospital-level confounders (adjusted rate ratio, 0.52; 95%CI, 0.51-0.54). Among 35,153 OHCA patients with return of spontaneous circulation, unadjusted neurologically favourable survival varied from 26.4% to 34.7% (rate difference, 8.3%; 95%CI, 6.6-10.1%); the East region had a significantly lower rate compared to the Midwest region (adjusted rate ratio, 0.72; 95%CI, 0.68-0.76).
CONCLUSION: In this prospective, nation-wide, population-based study in Japan, we found a two-fold regional difference in neurologically favourable survival after OHCA, suggesting regional disparities in prehospital care and in-hospital post-resuscitation care.