Association of Instrumental Activities of Daily Living, Physical Function, and Mental Health among Older Returnees after the Fukushima Daiichi Nuclear Power Station Accident

The 2011 Great East Japan Earthquake and consequent Fukushima Daiichi Nuclear Power Station accident caused a large-scale evacuation, generating various health issues. Although residents gradually returned, their independence of daily living and associated factors remain unknown. This study examines the hypothesis that physical and mental status are associated with the instrumental activities of daily living (IADL) of older returnees (65 years and above) after the disaster. Older returnees to Kawauchi Village, Fukushima Prefecture, located 20–30 km southwest of the power plants, were recruited. IADL was assessed using the Japan Science and Technology Agency Index of Competence, physical function via the 30-s chair stand test, and mental health via the Japanese version of the World Health Organization Five Well-Being Index. To examine the association of IADL and possible factors, a t-test or Pearson’s product-moment correlation coefficient was used, stratified by sex. The data of 29 participants (75.5 ± 7.4 years, 19 female) were analyzed. Physical function was associated with IADL in females. Mental health was associated with IADL in males and females. Taking measures to strengthen physical function in females, as well as to improve mental health in both sexes, for enhancing IADL ability could be beneficial.