Impact of the Great East Japan earthquake on out-of-hospital cardiac arrest with cardiac origin in non-disaster reas

BACKGROUND: To examine changes in the incidence of out-of-hospital cardiac arrest (OHCA) with cardiac origin in the non-disaster areas of Japan before and after the Great East Japan Earthquake of 11 March 2011. METHODS: The 35 prefectures in Japan with no dead or missing caused directly by the earthquake were defined as the non-disaster areas. Data of adult OHCA patients in the non-disaster areas from March 4 to 24 each year from 2005 to 2011 were obtained from the All-Japan Utstein Registry. Risk ratios (RRs) of OHCA incidence and 95% CIs were estimated for three specific weeks in 2011 (1 week before and 2 weeks after the earthquake) by applying multivariable Poisson regression model. Incidence in the corresponding periods of March 4-24 from 2005 to 2010 was set as the baseline risk. RESULTS: In the analyses from a total of 17,353 OHCA patients, the incidence statistically significantly increased in the first week after the earthquake in all adults (adjusted-RR=1.13, 95% CI=1.05 to 1.22, p=0.001) and in elderly women (adjusted-RR=1.23, 95% CI=1.11 to 1.37, p<0.001). CONCLUSIONS: The Great East Japan Earthquake caused the increase of OHCA among elderly women even in the non-disaster areas.