Differences in infant and child mortality before and after the Great East Japan Earthquake and Tsunami: a large population-based ecological study

OBJECTIVES: To examine associations between access to medical care, geological data, and infant and child mortality in the area of North-Eastern Japan that was impacted by the Great East Japan Earthquake and Tsunami (GEJET) in 2011. DESIGN: A population-based ecological study using publicly available data. SETTING: Twenty secondary medical areas (SMAs) in the disaster-affected zones in the north-eastern prefectures of Japan (Iwate, Fukushima and Miyagi). Participants: Children younger than 10 years who died in the 20 SMAs between 2008 and 2014 (n=1 748). Primary and secondary outcome measures: Multiple regression analysis for infant and child mortality rate. The mean values were applied for infant and child mortality rates and other factors before GEJET (2008–2010) and after GEJET (2012–2014). RESULTS: Between 2008 and 2014, the most common cause of death among children younger than 10 years was accidents. The mortality rate per 100 000 persons was 39.1±41.2 before 2011, 226.7±43.4 in 2011 and 31.4±39.1 after 2011. Regression analysis revealed that the mortality rate was positively associated with low age in each period, while the coastal zone was negatively associated with fewer disaster base hospitals in 2011. By contrast, the number of obstetrics and gynaecology centres (β=−189.9, p=0.02) and public health nurses (β=−1.7, p=0.01) was negatively associated with mortality rate per person in 2011. CONCLUSIONS: In 2011, the mortality rate among children younger than 10 years was 6.4 times higher than that before and after 2011. Residence in a coastal zone was significantly associated with higher child mortality rates.