The factor structure of the General Health Questionnaire (GHQ): a scaled version for general practice in Spain

BackgroundThe 28-item version of the General Health Questionnaire (GHQ-28) developed by Goldberg and Hillier in 1979 is constructed on the basis of a principal components analysis of the GHQ-60. When used on a Spanish population, a translation of the GHQ-28 developed for an English population may lead to worse predictive values.MethodsWe used our Spanish sample to replicate the entire process of construction of the GHQ-28 administered in a primary-care setting.ResultsTwo shorter versions were proposed: one with six scales and 30 items, and the other with four scales and 28 items.ConclusionsThe resulting GHQ-28 was a successful adaptation for use on the Spanish sample. When compared with the original version, only 21 items were the same. Moreover, contrary to the English version, which groups sleep problems and anxiety in the same scale, a scale with items related exclusively to ‘Sleep disturbances’ was found.