General Health Questionnaire (GHQ12): new evidence of construct validity.

This study aimed to gather evidence on the adequacy of the General Health Questionnaire (GHQ-12) in Brazil, considering a random sample of Brazilian physicians. Specifically aimed: (1) to test the GHQ-12 bifactor structure compared to alternative models, (2) to check its factorial invariance regarding to gender and the diagnosis of mental and behavioral disorders, and (3) to know the association of this measure with indicators of poor health (e.g., suicidal thoughts, decreased libido, medication use). The study included 1,085 physicians with a mean age of 45.7 (SD = 10.6), mostly male (61.5%), married (72.6%) and Catholic (59.2%). They answered the GHQ-12, the Positive and Negative Suicidal Ideation Inventory, and demographic questions. The best fit model was the bifactor structure composed of anxiety and depression, in addition to a general dimension, which presented Cronbach's alpha, McDonald's ω and composite reliability higher than 0.70 just for a general fact. Psychological distress scores correlated with suicidal ideation and indicators of health and sexual satisfaction. This is a psychometrically suitable instrument that can be used in terms of its total, but its specific factors need to be used with caution.