Trajectories of Liver Dysfunction and Long-term Evacuation Status after the Great East Japan Earthquake: the Fukushima Health Management Survey

Objectives In the Fukushima Health Management Survey (FHMS), the association between subsequent evacuation status, such as return and continued evacuation, and trends in liver dysfunction remains unclear. Therefore, this study evaluated this association using FHMS data through fiscal year (FY) 2018. Methods The 34,435 (14,063 men and 20,372 women) study participants underwent a Comprehensive Health Check, answered the Mental Health and Lifestyle Survey questionnaire in FY 2011, and were followed up until FY 2018. The participants were classified by trajectory for liver dysfunction using group-based trajectory modeling, and we examined differences in study items as of FY 2012 by each trajectory. Additionally, we divided the 13 municipalities, including evacuation zones, into partially evacuated, returnable, and difficult-to-return areas according to the lifting of evacuation orders as of FY 2018, and logistic regression modeling was used to investigate the association between long-term post-disaster evacuation status and the liver dysfunction trajectory. Results Participants were classified by group-based trajectory modeling into Group 1 (continuously low prevalence rate; 62.2%), Group 2 (improvement from high prevalence in FY2011; 10.8%), Group 3 (like group 1 prevalence in FY2011 but increasing afterwards; 11.2%), and Group 4 (continuously high prevalence; 15.8%), respectively. Multivariate logistic regression modeling revealed the difficult-to-return areas and returnable areas had a higher risk of being in the Group 2, Group 3, and Group 4, compared with the partially evacuated areas. Conclusions Our findings suggest that liver dysfunction is more likely to persist in areas where evacuation was more prolonged.