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

Two years after the Niigata-Chuetsu Earthquake, subjects who experienced the earthquake were asked to reply to questionnaires prepared to measure the level of their psychological distress. They lived in the area both when the earthquake occurred and when this survey was carried out. They were recruited by random sampling stratified by geographic areas affected by the earthquake. Psychological distress was measured by using the Japanese version of the 12-item General Health Questionnaire (GHQ-12) [1] . The GHQ-12 was scored by the binary [2] , chronic and Likert scoring [18] . The proportions of subjects who suffering psychological distress were estimated by using cutoff points for GHQ scores. We used average GHQ scores as the cutoff points as recommended [19] .