Distance to retail stores and risk of being homebound among older adults in a city severely affected by the 2011 Great East Japan Earthquake

Background: after the Great East Japan Earthquake in 2011, inactivity and the homebound status of older victims in affected areas have been a serious public health concern owing to the victims' prolonged existence as evacuees in mountainous areas. Objective: to evaluate the association between distances to retail stores and risks of being homebound. Design: secondary analysis of cross-sectional interview survey data with a geographical information analysis. Setting: Rikuzentakata, Iwate, a municipality seriously damaged by the 2011 earthquake and tsunami. Subjects: all Rikuzentakata residents aged 65 or older except for those living in temporary housing (n = 2,327). Methods: we calculated road distances between each residential address and retail stores, hawker sites and shopping bus stops, accounting for the extra load caused by walking on slopes. The prevalence ratio of being homebound adjusted for age, source of income and morbidity by road distance was estimated using Poisson regression with a generalised estimating equation. Results: those living at distances of 1,200 m or more were 1.78 (95% confidence intervals, 1.03–3.08) times more likely to be homebound (going out only every 4 or more days a week) among men and 1.85 (1.13-3.02) among women, compared with those residing in places <400 m from retail stores or shopping bus stops. The distances were reduced by new hawker and shopping bus services, but the improvements varied greatly across the districts. Conclusions: access to daily needs is essential to prevent homebound status. Post-disaster community diagnosis in terms of the built environment is important for strategic community restoration.