The Physical Health Questionnaire (PHQ): construct validation of a self-report scale of somatic symptoms.

The authors report the results of 3 studies that were conducted to evaluate the psychometric properties of the Physical Health Questionnaire (PHQ), a brief self-report scale of somatic symptoms. In Study 1, exploratory factor analysis results revealed 4 empirically distinct dimensions of somatic symptoms: gastrointestinal problems, headaches, sleep disturbances, and respiratory illness. In Study 2, this structure was replicated using confirmatory factor analysis, and correlations of the PHQ dimensions with measures of negative affect, psychological health, and job performance provided further validity evidence. In Study 3, a minor revision to the wording of several items helped to address the limitations of one of the PHQ subscales. Together, these results provide evidence of the construct validity of the PHQ.