Objective: The 12-item General Health Questionnaire (GHQ-12) has been used extensively in various settings across different cultures. This study was conducted to determine the thresholds associated with optimum sensitivity and specificity for the GHQ-12 in Korean adults.
Methods: Data was acquired from a sample of 6,510 Korean adults, ages 18 to 64 years old, who were selected from the 2005 Census (2,581 men and 3,929 women). Participants completed the GHQ-12 and the Korean Composite International Diagnostic Interview (K-CIDI). Receiver Operating Characteristic (ROC) curve analysis was conducted.
Results: The mean GHQ-12 score for the total sample was 1.63 (SD 1.98). The internal consistency of the GHQ-12 was good (Cronbach's α=0.72). Results from the ROC curve indicated that the GHQ-12 yielded greater accuracy when identifying mood and anxiety disorders than when identifying all mental disorders as a whole. The optimal threshold of the GHQ-12 was either 1/2 or 2/3 point depending on the disorder, but was mainly 2/3.
Conclusion: The Korean version of the GHQ-12 could be used to screen for individuals at high risk of mental disorders, namely mood and anxiety disorders.
Keywords: GHQ-12; Optimal threshold; Psychiatric diagnoses; Sensitivity; Specificity.