title: Can Community Social Cohesion Prevent Posttraumatic Stress Disorder in the Aftermath of a Disaster? A Natural Experiment From the 2011 Tohoku Earthquake and Tsunami.
abstract: In the aftermath of a disaster, the risk of posttraumatic stress disorder (PTSD) is high. We sought to examine whether the predisaster level of community social cohesion was associated with a lower risk of PTSD after the earthquake and tsunami in Tohoku, Japan, on March 11, 2011. The baseline for our natural experiment was established in a survey of older community-dwelling adults who lived 80 kilometers west of the epicenter 7 months before the earthquake and tsunami. A follow-up survey was conducted approximately 2.5 years after the disaster. We used a spatial Durbin model to examine the association of community-level social cohesion with the individual risk of PTSD. Among our analytic sample (n = 3,567), 11.4% of respondents reported severe PTSD symptoms. In the spatial Durbin model, individual- and community-level social cohesion before the disaster were significantly associated with lower risks of PTSD symptoms (odds ratio = 0.87, 95% confidence interval: 0.77, 0.98 and odds ratio = 0.75, 95% confidence interval: 0.63, 0.90, respectively), even after adjustment for depression symptoms at baseline and experiences during the disaster (including loss of loved ones, housing damage, and interruption of access to health care). Community-level social cohesion strengthens the resilience of community residents in the aftermath of a disaster.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hikichi
authors.forename: Jun
authors.initials: J
authors.lastname: Aida
authors.forename: Toru
authors.initials: T
authors.lastname: Tsuboya
authors.forename: Katsunori
authors.initials: K
authors.lastname: Kondo
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kawachi
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003863:Depression / Q000453:epidemiology / Q000523:psychology; D055866:Earthquakes / Q000706:statistics & numerical data*; D005260:Female; D006297:Health Services Accessibility; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D055500:Resilience, Psychological; D012737:Sex Factors; D012944:Social Support; D012959:Socioeconomic Factors; D013313:Stress Disorders, Post-Traumatic / Q000453:epidemiology / Q000517:prevention & control* / Q000523:psychology; D017741:Survivors; D057192:Tsunamis / Q000706:statistics & numerical data*
keywords: Japan; community social cohesion; disaster; disaster resilience; posttraumatic stress disorder; spatial Durbin model