Sleep disturbance of evacuees in Minamisanriku town after great east Japan earthquake: Risk factors and treatment

In 2011, Minamisanriku Town lost all of its medical facilities during the Great East Japan Earthquake. Using 10,459 anonymized disaster medical records of affected people in Minamisanriku Town, we assessed the prevalence and risk factors of sleep disturbance, which is known to exacerbate non-communicable diseases (NCDs) and anxiety disorder. Because sleep disturbance is a part of mental health issues, we divided the patients into two groups: patients (n = 492) with mental health issues other than sleep disturbance and the remaining (n = 9,967) with other comorbidities. Out of 492 patients with mental health issues, 295 patients (60.0%, 114 male, 158 female and 23 unknown) had sleep disturbance who might have required specific treatments. Out of the remaining 9,967 patients, 1,203 patients (12.1%, 361 male and 769 female and 73 unknown) had sleep disturbance. Univariate and multivariate analyses of the 9,967 patients revealed that the odds ratio (OR) of sleep disturbance was higher for female (OR 1.95), elderly persons over 60 (OR 16.15) and residing in evacuation centers (OR 1.36). Patients with two or more NCD had higher risk (OR 1.42). Importantly, sleep disturbance affects younger patients without NCD residing in evacuation center. Emergency medical teams most frequently prescribed benzodiazepines both for sleep induction and anxiolysis. In addition to high risk groups (female, older, with other mental health issues, residing in evacuation center), it is important to survey sleep disturbance in younger and healthier populations especially in evacuation centers and to provide psychosocial and medical support for them.