Background: In order to find factors associated with earthquake deaths due to the Great Hanshin-Awaji earthquake, we conducted a descriptive epidemiological and a case-control study.
Methods: The study area was Nishinomiya city. Earthquake mortality was calculated by age group, sex and the degree of damage to dwelling. Cases in the case-control study included all 1,104 earthquake-caused deaths. Randomly selected survivors living in the same neighborhood and matching sex, age, and the degree of damage to dwelling were used as controls. Seven kinds of information about subject's health and welfare on January 16, one dey before the earthquake, were used for analysis.
Results: The likelihood of earthquake-caused mortality steadily increased after 50 years of age. Mortality among people who lived in completely destroyed dwellings was much higher than that among people who lived in intact or partially-destroyed dwellings. In the case-control study, a significant risk factor for earthquake death was physical disability (odds ratio (OR) = 1.9; 95% confidence interval (95% C.I.), 1.0 to 3.34). When the analysis was limited to those who lived in intact or partially-destroyed dwellings, the odds ratio of physical disability increased to 5.6 (95% C.I., 1.6 to 19.8).
Conclusions: The most important risk factors were age and degree of damage to dwelling. Physical disability was suggested as a risk factor.