Posttraumatic stress response following the loss of significant close others in the Great East Japan Earthquake: Fukushima Health Management Survey.

During the Great East Japan Earthquake, many people experienced the loss of family and friends, among other traumatic events. This study sought to clarify the impact of the loss of significant close others on posttraumatic stress symptoms (PTSS), as well as the factors associated with PTSS, among individuals who experienced the loss of significant close others (i.e., bereaved group). Self-administered questionnaires were mailed to men and women (N = 180,604) aged 16 years and older living in municipalities that included evacuated areas surrounding the Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Station, which was significantly damaged following an earthquake and tsunami in March 2011, causing subsequent radiation leakage; this mailing yielded a 40.7% response rate, with 57,388 valid responses, in 2012. We used the Posttraumatic Stress Disorder Checklist-Specific (PCL-S) to measure PTSS as the outcome variable. Loss of significant close others in the disaster and respondents' relationship with the deceased constituted the explanatory variables. Basic characteristics and disaster-related factors were the confounding variables. Data were analyzed using chi-square tests and logistic regression analyses. The bereaved group showed more severe PTSS than the nonbereaved group, aOR = 1.58, 95% CI [1.50, 1.67]. The risk of developing PTSS increased if the deceased was a respondent's spouse, aOR = 1.67, 95% CI [1.22, 2.29]; child, 1.51 [1.01, 2.25]; or friend, 1.33 [1.16, 1.53]. Individuals who lose significant close others, including both family and friends, in disasters require close mental health care and, if necessary, should be referred for psychiatric treatment.