Factor Structure, Longitudinal Invariance and Criterion Validity of the Hospital Anxiety and Depression Scale in Cardiac and Hypertensive Patients

The Hospital Anxiety and Depression Scale (HADS) is a commonly used selfreport measure of anxiety and depressive symptoms. However, there is a strong debate about its dimensionality. The present study aimed at assessing factor structure, longitudinal measurement invariance and criterion validity of the HADS in a sample of cardiac and hypertensive patients. Self-report measures were administered at baseline and 6 months later to 195 cardiac and 338 hypertensive patients, ranging in age from 20 to 79. Confirmatory factor analysis was performed to evaluated the best fitting structure and longitudinal invariance of the HADS. Concurrent and predictive validity were assessed considering relationships among HADS dimensions and several measures of health and well-being, such as: illness perception, self-efficacy beliefs in managing disease, satisfaction with life, quality of life, and perceived health status. Results demonstrated the superior fit of a threefactor model of depression, psychic anxiety and psychomotor agitation. Moreover, this structure appeared to be stable and partially invariant over time. Finally, HADS dimensions were correlated with concurrent and subsequent measures of health and quality of life. The HADS was confirmed to be a reliable and valid measure of psychological distress in cardiac and hypertensive patients.