[Environmental risks to housing and living arrangements among older survivors of the Great East Japan Earthquake and their relationships with housing type: The RIAS Study].

Objective　Over the course of their lives, people spend most of their time in the home environment. The Community-based Integrated Care System 2018 by the Ministry of Health, Labour and Welfare in Japan declared the importance of "housing" and "living arrangements" as essential elements to enable older adults to live independently and to protect their privacy and dignity in their communities. The present study aims to clarify the relationship between current housing type and "housing" and "living arrangements" among older survivors of the Great East Japan Earthquake (GEJE).Methods　We used data obtained from 3,856 participants, aged 65 years or older, in the Research project for prospective Investigation of health problems Among Survivors of the GEJE (RIAS). Housing types were categorized as follows: "same housing," "temporary housing," "disaster public housing," "new housing" (in a different area), and "others." Healthy housing scores were calculated using a housing health checklist from the Nationwide Smart Wellness Housing Survey in Japan. "Living arrangements" were assessed based on residential status, social network, and social capital. To determine the risks associated with each "housing" and "living arrangement" category, we used multivariate logistic and linear regression models.Results　The number of participants in each housing type was as follows: 2,531 in "same housing," 146 in "temporary housing," 234 in "disaster public housing," 844 in "new housing," and 101 in "others." Compared with those living in "same housing," those living in "disaster public housing," "new housing," and "others" had a significantly higher healthy housing score, whereas those living in "temporary housing" had a lower score. However, with regards to "living arrangements," the number of residents who were living alone was significantly higher among those in "disaster public housing," and those living in "disaster public housing" as well as "new housing" had low social capital compared with those living in "same housing." The likelihood of having a poor social network was substantially higher for those living in "disaster public housing." Sub-scale analyses indicated that "disaster public housing" was associated with less family support, whereas "new housing" was associated with less support from friends.Conclusion　The present results indicate that older survivors-regardless of whether they live in the existing community-find it challenging to establish new social capital and social networks in a new location without the presence of "someone" they knew before the disaster.