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

Confirmatory factor analyses were performed for various models, including the model that we found by exploratory factor analysis [5, 7, 16] . Among the various models, the two-factor model found by exploratory factor analysis showed more favorable fitting measures than those of the one-factor model and models consisting of three or more factors. Some of the results are presented in Table 2 . In addition, the two-factor model using chronic method showed fitting measures superior to those of binary method and Likert method (Table 2) , although there were no statistical differences in the fitting measures between the three scoring methods. Therefore, we used chronic method in subsequent analyses. The internal consistency of each factor in all three scoring methods was satisfactory, because Cronbach's alpha score for two factors ranged from 0.87 to 0.90.