Socioeconomic status (SES) and lifestyle-related factors are determinants of subjective health. However, changes in SES are inevitable in times of natural disaster, while lifestyle-related factors remain modifiable. The aim of this study was to use a cross-sectional approach to examine lifestyle-related factors that may attenuate the negative impact of disaster-induced changes in SES on poor subjective health.
We analyzed 33,350 men and women aged 20–64 years who were living in evacuation zones due to the radiation accident in Fukushima, Japan. Disaster-induced changes in SES were defined by living arrangements and working conditions. Using Poisson regression analysis adjusted for confounders (model 1) and lifestyle-related factors as intermediate variables (model 2), we compared the prevalence ratios (PRs) of poor subjective health of participants who did not undergo disaster-induced changes in SES (did not become unemployed, income did not decrease, and living in relative’s home/own home) with that of participants who did undergo disaster-induced changes in SES (became unemployed, decreased income, or lived in an evacuation shelter, temporary housing, or rental housing/apartment). We calculated the percentage of excess risks explained by lifestyle-related factors as follows: ((PR model 1 − PR model 2)/(PR model 1–1)) × 100.
Disaster-induced changes in SES were significantly associated with poor subjective health. The PRs (95% CIs) among participants who underwent disaster-induced changes in SES were 2.02 (1.81–2.24) for men and 1.80 (1.65–1.97) for women. After adjusting for lifestyle-related factors, we found that the PRs in men and women were remarkably attenuated, decreasing to 1.56 (1.40–1.73) and 1.43 (1.31–1.55), respectively. Controlling for lifestyle-related factors resulted in PR attenuation by 45.1% (men) and 46.3% (women). Satisfaction of sleep and participation in recreation and community activity particularly contributed to this attenuation.
While disaster-induced changes in SES are unavoidable, lifestyle-related factors have the potential to attenuate the impact of these changes on poor subjective health.