Implications for Social Support on Prolonged Sleep Difficulties among a Disaster-Affected Population: Second Report from a Cross-Sectional Survey in Ishinomaki, Japan

• Published in: PloS one 2015-06, Vol.10 (6), p.e0130615-e0130615
• Main Authors: Matsumoto, Shoko, Yamaoka, Kazue, Inoue, Machiko, Inoue, Mariko, Muto, Shinsuke
• Format: Article
• Language: English
• Subjects: Adult; Aged; Councils; Cross sections; Cross-Sectional Studies; Disasters; Earthquake damage; Earthquakes; Emotions; Female; Housing; Humans; Japan - epidemiology; Logistic Models; Male; Medicine; Middle Aged; Population; Public health; Regression analysis; Regression models; Seismic activity; Sleep; Sleep Initiation and Maintenance Disorders - epidemiology; Sleep Initiation and Maintenance Disorders - psychology; Social aspects; Social factors; Social interactions; Social networks; Social Support; Stress; Structural damage; Studies; Surveys; Tsunamis
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0130615

This study aimed to investigate the role of social factors, especially social support for sleep, among victims living at home around 1-2 years after the Great East Japan Earthquake and tsunami. A cross-sectional household survey was conducted between May and December 2012 (14-21 months after the disaster) in the Ishinomaki area, Japan. Univariate and multivariate logistic regression models were used to examine the association between social factors, including social support, and prolonged sleep difficulties (persisting over 1 month). Social support was divided into three functions: emotional, informational, and instrumental support. Data were obtained on 2,593 individuals who were living at home after the disaster. The prevalence of prolonged sleep difficulties was 6.9% (5.8% male, 7.7% female). This study showed that lack of social support has a stronger association with prolonged sleep difficulties than non-modifiable or hardly modifiable consequences caused directly by the disaster, i.e., severity of home damage, change in family structure and income. Among the three dimensions of social support, lack of emotional support showed the strongest association with prolonged sleep difficulties. Social support, especially emotional support, may positively affect sleep among victims living at home around 1-2 years after a disaster.