Anxiety and depression in cardiac patients: A psychometric evaluation of the Hospital Anxiety and Depression Scale; HADS, and a longitudinal investigation of exercise, gender and affective functioning

Gender differences are apparent in both the affective functioning and exercise behaviour of cardiac patients. Specifically, female cardiac patients demonstrate more anxiety and depression, and reduced exercise compared to males. Accordingly, gender appropriate screening measures and interventions are needed. In studying a diverse sample of cardiac patients over two years, the objectives of the first investigation were to (1) examine the factor structure of the HADS, and (2) test measurement invariance between genders. The aims of the second study were to (1) examine the prevalence of autonomic anxiety, negative affect and depression, and (2) determine whether gender moderated the exercise/affective relationships, and (3) evaluate whether exercise mediated the gender/affective relationships. 801 cardiac inpatients completed questionnaires including the HADS at baseline, 6 months, 12 months and 24 months post-discharge. Confirmatory factor analysis consistently supported a three-factor structure of the HADS, with the best fitting model comprised of negative affect, autonomic anxiety and depression. Structural equation modeling showed that the HADS was invariant by gender among cardiac patients. Repeated measures analysis of covariance (ANCOVA) revealed that female cardiac patients had greater autonomic anxiety, negative affect and depression and reduced exercise compared to male cardiac patients at all time points. Although exercise was significantly related to affective outcomes at various time points for both men and women, gender did not moderate any of the exercise/affective relationships, and exercise did not mediate any of the gender/affective relationships. In summary, the HADS can be appropriately used with both male and female cardiac patients to assess three domains of psychological distress. Future investigations should consider the predictive validity and relevance of the HADS subscales with respect to diagnostic distinctions and clinical outcomes among cardiac patients and other clinical populations. In addition, further research is needed to clarify the complex relationships between gender and the affective functioning of cardiac patients.