title: Do community- and individual-level social relationships contribute to the mental health of disaster survivors?: A multilevel prospective study after the Great East Japan Earthquake.
abstract: Disasters greatly threaten the health and lives of people all over the world. Japan experienced severe damage following the Great East Japan Earthquake on March 11, 2011, and some survivors continue to live in prefabricated temporary housing, built collectively in damaged areas. Previous studies have shown that social relationships in such communities have the potential to protect the mental health of disaster survivors. We examined the association between survivors' social support and social participation in 2012 and their psychological distress in 2013 using the K6 scale. Self-reported questionnaires were distributed to all 15,979 households in prefabricated temporary housing in eight municipalities in Miyagi prefecture in 2012, and 19,284 adults from 9366 (58.6%) households responded. One year later, 10,880 adults responded to a follow-up survey. Multivariate multilevel linear regression analyses with multiply imputed datasets showed that survivors' psychological distress at follow-up significantly differed between communities (community-level variance [standard error] = 0.38 [0.13]). The variance was reduced to 0.25 [0.09] after considering individual demographic characteristics and psychological distress at baseline. Individual- and community-level social relationships of 7.1% and 15.8%, respectively, explained the difference. After adjusting for covariates including K6 scale at baseline, individual-level social support, community-level social support, and individual-level social participation were significantly associated with low psychological distress at follow-up (coefficients [95% confidence intervals] were: -0.54 [-0.79, -0.30]; -0.43 [-0.72, -0.14]; and -0.22 [-0.40, -0.04], respectively). Community-level social participation was not significantly associated with psychological distress. The present study showed that: 1) survivors' psychological distress varied between temporary housing communities in 2013; 2) individual- and community-level social relationships contributed to the difference; and 3) individual- and community-level social relationships in 2012 were protectively associated with survivors' psychological distress in 2013. Promoting social relationships in communities after disasters might decrease disaster survivors' psychological distress.
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Matsuyama
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Sendai, Japan; Miyagi Prefectural Government Office, Sendai, Japan. Electronic address: j-aida@umin.ac.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Aida
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hase
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Shihoko
authors.initials: S
authors.lastname: Koyama
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Sendai, Japan; Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, USA.
authors.forename: Toru
authors.initials: T
authors.lastname: Tsuboya
authors.affiliation: Department of International and Community Oral Health, Tohoku University Graduate School of Dentistry, Sendai, Japan; Disaster Medical Science Division, Disaster Related Oral Health, International Research Institute of Disaster Science, Sendai, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Osaka
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D055866:Earthquakes / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008603:Mental Health / Q000592:standards* / Q000706:statistics & numerical data; D008875:Middle Aged; D011446:Prospective Studies; D012944:Social Support; D013315:Stress, Psychological / Q000150:complications; D011795:Surveys and Questionnaires; D017741:Survivors / Q000523:psychology* / Q000706:statistics & numerical data
keywords: Earthquake; Geographical difference; Mental health; Social participation; Social support