Measuring HRQoL following heart valve surgery: the HeartQoL questionnaire is a valid and reliable core heart disease instrument

Purpose Patient-reported health-related quality of life is a complementary healthcare outcome and important when assessing treatment efficacy. Using COSMIN methodological recommendations, this study evaluates the validity and reliability of a core heart disease-specific health-related quality of life questionnaire, the HeartQoL questionnaire (Danish version) in a sample of patients following heart valve surgery. Design This project involved a cross-sectional validity study and a test–retest reliability study. Methods Eligible patients completed the HeartQoL, the SF-36 health survey questionnaire, and the Hospital Anxiety and Depression Scale following heart valve surgery. Construct validity was tested using a priori hypotheses. Internal consistency reliability was assessed with Cronbach’s alpha. An independent sample of patients participated in the test–retest study and reproducibility was determined with relative [intra-class correlation coefficient (ICC)] and absolute reliability [standard error of measurement (SEM) and smallest detectable change (SDC)]. Results Internal consistency was high with Cronbach’s alpha ≥ 0.87. ICC was 0.86–0.92. SEM ranged from 0.17 to 0.26 points and SDC ranged from 0.5 to 0.7 points. Construct validity was confirmed with 87% of all a priori hypotheses for predicted variables. Conclusions The HeartQoL questionnaire demonstrates acceptable construct validity, internal consistency, and test–retest reproducibility in patients following heart valve surgery. Future studies should focus on assessing the responsiveness of the HeartQoL questionnaire over time and following heart valve surgery.