Factor structure of the General Health Questionnaire (GHQ-12) in subjects who had suffered from the 2004 Niigata-Chuetsu Earthquake in Japan: a community-based study

Toyabe, Shin-ichi; Shioiri, Toshiki; Kobayashi, Kuriko; Kuwabara, Hideki; Koizumi, Masataka; Endo, Taro; Ito, Miki; Honma, Hiroko; Fukushima, Noboru; Someya, Toshiyuki; Akazawa, Kouhei

There are several limitations in this study. First, there were no non-exposed or pre-earthquake control subjects in this study. Second, no correspondence between the subjects in the first survey and those in the second survey exists. The backgrounds of the subjects in the two surveys were different, and the difference was especially remarkable in the gender ratio of study subjects. The male-to-female ratio was 55%:45% in the first survey, but it was 62%:38% in the second survey. Therefore, we did not directly compare the results of the two surveys but we used the results of first survey just for reference to the second survey. Nevertheless, it is obvious that the subjects were affected by matters related to the factor 'social dysfunction' two years after the earthquake and that subjects more than 80 years old were more affected than younger subjects. Differences of lower scale points by age group of subjects Figure 2 Differences of lower scale points by age group of subjects. The relationship between age of subjects and GHQ scores is shown as mean and standard deviation values. The data obtained two years after the earthquake (second survey) are shown with the data obtained five months after the earthquake (first survey). Trends of GHQ scores with increasing age of subjects were analyzed by ANOVA (ANOVA) with Scheffe post hoc tests and Jonckheere-Terpstra Test (JT). The p value of each test is shown in the plot. The factor I score of age group years 40-49 was significantly lower than groups years 65-79 and 80-(*) in the first survey. Age group years 80-showed significantly higher factor I score than other age groups ( †).