Six-year follow-up study of residential displacement and health outcomes following the 2011 Japan Earthquake and Tsunami

Abstract

Significance The long-term health consequences of residential relocation following large-scale natural disasters remain poorly understood. We implemented a longitudinal study following the 2011 Earthquake and Tsunami in which survivors were relocated to temporary housing by different means: group relocation versus individual relocation. Group relocation was adversely associated with weight gain and depressive symptoms. An implication of our findings is that moving survivors into a highly dense environment conducive to social gatherings may paradoxically promote unhealthy changes in behavior (e.g., drinking and snacking). By contrast, we found that individual relocation was associated with deteriorated instrumental activities of daily living and cognitive function. The resettlement of survivors can have complex effects on physical and mental well-being, depending on the method of relocation. Studies examining the long-term health consequences of residential displacement following large-scale disasters remain sparse. Following the 2011 Japan Earthquake and Tsunami, victims who lost their homes were resettled by two primary means: 1) group relocation to public housing or 2) individual relocation, in which victims moved into public housing by lottery or arranged for their own accommodation. Little is known about how the specific method of residential relocation affects survivors’ health. We examined the association between residential relocation and long-term changes in mental and physical well-being. Our baseline assessment predated the disaster by 7 mo. Two follow-up surveys were conducted ∼2.5 y and 5.5 y after the disaster to ascertain the long-term association between housing arrangement and health status. Group relocation was associated with increased body mass index and depressive symptoms at 2.5-y follow-up but was no longer significantly associated with these outcomes at 5.5-y follow-up. Individual relocation at each follow-up survey was associated with lower instrumental activities of daily living as well as higher risk of cognitive impairment. Our findings underscore the potential complexity of long-term outcomes associated with residential displacement, indicating both positive and negative impacts on mental versus physical dimensions of health.