Social ties may play a critical role in mitigating sleep difficulties in disaster-affected communities: a cross-sectional study in the Ishinomaki area, Japan.
OBJECTIVE
We examined the association between social factors and sleep difficulties among the victims remaining at home in the Ishinomaki area after the Great East Japan Earthquake and Tsunami and identified potentially modifiable factors that may mitigate vulnerability to sleep difficulties during future traumatic events or disasters.


METHODS
A cross-sectional household survey was conducted from October 2011 to March 2012 (6-12 mo after the disaster) in the Ishinomaki area, Japan. Univariate and multivariate logistic regression models were used to examine associations between social factors and sleep difficulties.


METHODS
We obtained data on 4,176 household members who remained in their homes after the earthquake and tsunami.


METHODS
N/A.


RESULTS
Sleep difficulties were prevalent in 15.0% of the respondents (9.2% male, 20.2% female). Two potentially modifiable factors (lack of pleasure in life and lack of interaction with/visiting neighbors) and three nonmodifiable or hardly modifiable factors (sex, source of income, and number of household members) were associated with sleep difficulties. Nonmodifiable or hardly modifiable consequences caused directly by the disaster (severity of house damage, change in family structure, and change in working status) were not significantly associated with sleep difficulties.


CONCLUSIONS
Our data suggest that the lack of pleasure in life and relatively strong networks in the neighborhood, which are potentially modifiable, might have stronger associations with sleep difficulties than do nonmodifiable or hardly modifiable consequences of the disaster (e.g., house damage, change in family structure, and change in work status).
Graduate School of Public Health, Teikyo University, Tokyo, Japan.
Shoko
S
Matsumoto
Graduate School of Public Health, Teikyo University, Tokyo, Japan.
Kazue
K
Yamaoka
Department of Community Medicine, Teikyo University School of Medicine, Tokyo, Japan.
Machiko
M
Inoue
Health and Life Revival Council in the Ishinomaki District (RCI).
Shinsuke
S
Muto
D000368:Aged; D019058:Community Networks; D003430:Cross-Sectional Studies; D004190:Disasters; D055866:Earthquakes; D004651:Employment / Q000191:economics; D005191:Family Characteristics; D005260:Female; D006240:Happiness; D006798:Housing; D006801:Humans; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012890:Sleep; D012893:Sleep Wake Disorders / Q000453:epidemiology / Q000517:prevention & control / Q000523:psychology*; D012944:Social Support; D017741:Survivors / Q000523:psychology*; D057192:Tsunamis
Cross-sectional household survey; Great East Japan Earthquake and Tsunami; natural disaster; sleep difficulties; social network