Validation of the German HeartQoL: a short health-related quality of life questionnaire for cardiac patients

Purpose The aim of this study was to evaluate psychometric properties of the core disease-specific 14-item German HeartQoL questionnaire. Methods As an extension of the international HeartQol Project, cross-sectional and longitudinal health-related quality of life (HRQL) data were collected from 305 patients with angina ( N = 101), myocardial infarction ( N = 123), or ischemic heart failure ( N = 81) in Austria and Switzerland using German versions of the HeartQoL, the Short Form-36 Health Survey (SF-36), and the Hospital Anxiety and Depression Scale. The underlying factor structure was examined with Mokken Scaling analysis; then convergent, divergent, and discriminative validity, internal consistency reliability, and responsiveness were assessed. Results The highest HRQL scores were reported by patients with myocardial infarction followed by ischemic heart failure and then angina. The two-factor structure was confirmed with strong physical, emotional, and global scale H coefficients (> .50). Divergent and convergent validity (from r = .04 to .78) were shown for each diagnosis; discriminative validity was verified as well (partially: age, sex, and disease severity; largely: SF-36 health status/transition; totally: anxiety and depression). Internal consistency reliability was excellent (Cronbach’s alpha = .91). In terms of responsiveness, physical and global scale scores improved significantly after percutaneous coronary intervention ( p < .01) while after cardiac rehabilitation all scale scores improved significantly ( p < .001). Conclusions The German HeartQoL questionnaire is a valid and reliable HRQL instrument with these data supporting its potential use in clinical practice and research to assess and compare HRQL in German-speaking patients with ischemic heart disease. The shortness of the tool may prove to be helpful particularly in clinical practice.