Protocol and research perspectives of the ToMMo child health study after the 2011 great east Japan earthquake

Residents of areas affected by the Great East Japan Earthquake may suffer from diseases or health problems. We are conducting a cross-sectional study from 2012 to 2015 to investigate and address the health needs of schoolchildren affected by this disaster. In this paper, we describe the protocol and research perspectives of our long-term child health study, and present the results obtained immediately after the disaster. The parent-administered questionnaire includes the International Study of Asthma and Allergies in Childhood questionnaire for asthma and eczema symptoms, the Strengths and Difficulties Questionnaire (SDQ), and a questionnaire on influenza infection and vaccination status. In 2012, we distributed the questionnaire to 3,505 (2^nd, 4^th, 6^th, and 8^th graders) in three municipalities located in southern coastal area among the 28 municipalities, and 1,277 (36.4%) returned the completed questionnaire. Mean age was 11.1 ± 2.2 years old. The number of children with symptoms of wheeze and eczema in the past 12 months was 146 (11.4%) and 199 (15.6%), respectively. The SDQ total difficulties score revealed 174 (13.6%) children with some form of difficulty in their daily lives. From May 2011 to April 2012, 195 (15.3%) and 649 (50.8%) children received the influenza vaccination once and twice, respectively, and 532 (41.7%) had suffered from influenza. The prevalence of eczema symptoms or some form of difficulty was higher than the Japanese average. However, careful interpretation was required because of potential self-selection bias from the low response rate. We will continue this study of schoolchildren to provide aggregate findings.