The best thresholds and the screening features among the three scoring methods of the 12-item General Health Questionnaire

Objective To explore the best thresholds and the screening features among the three scoring methods of the GHQ-12. Methods The sample was a qualify control data of epidemiological survey of mental disorders in Xiamen, and the tools of the GHQ-12 for the screening, Structured Clinical Interview for DSM-Ⅳ Axis Ⅰ Disorders-Patient Edition for the diagnosis, and the sensitivity, specificity and the area under the Receiver Operating Characteristic cure were analyzed. Results 1004 subjects completed the screening and the diagnosis, and the total score of CHQ by Liker scoring method was the highest, and C-GHQ scoring method was larger than GHQ standard method (χ2=1970.89,P<0.01).The area under the Receiver Operating Characteristic cure for the standard scoring method was 0.780, the Likert scoring method and the C-GHQ scoring method were 0.811, 0.809 respectively. Among the threshold 1/12 with GHQ standard method, (11-12)/36 with Likert method, 5/12 with C-GHQ method, the area under the Receiver Operating Characteristic cure for the mood disorders was highest, and anxiety disorders was larger than organic mental disorders. Conclusion The best thresholds score with the standard scoring method is 1/12, the Likert scoring method and the C-GHQ scoring method are (11-12)/36, 5/12 respectively. The three scoring methods are the most suitable to screen mood disorders with high stability. The three scoring methods show different screening features, and should be selected according to their research purposes. Key words: Mental disorders; ROC curve; Epidemiology; Questionnaires