Validity and reliability of the HeartQoL questionnaire in a large sample of stable coronary patients: The EUROASPIRE IV Study of the European Society of Cardiology

Background The aim of this study was to investigate the validity and reliability of the HeartQoL instrument in a population of stable coronary patients. Design Analyses are based on the cross-sectional EUROASPIRE IV (EUROpean Action on Secondary and Primary prevention through Intervention to Reduce Events) survey. Methods Patients with a diagnosis of coronary heart disease were examined and interviewed 6 months to 3 years after their coronary event. During the interview patients were asked to fill out the HeartQoL health-related quality of life questionnaire as well as the EQ-5D and the hospital anxiety and depression scale questionnaire. Psychometric analyses assessing the reliability and validity of the HeartQoL instrument were performed. Results A total of 7449 patients completed the HeartQoL instrument. Cronbach's alpha indicated excellent internal consistency for the global HeartQoL scale (=0.92) and the physical subscale (=0.91) and good internal consistency for the emotional subscale (=0.87). Factor analysis confirmed the two-dimensional construct although mixed results were found regarding the model fit. Discriminative validity analysis confirmed better HeartQoL results in men, younger patients and higher educated persons. Likewise, convergent validity was confirmed with moderate to strong correlations among hypothesised constructs. Conclusion Overall, psychometric analyses of the HeartQoL instrument in a population of patients with stable coronary heart disease showed good reliability and validity both at the European as well as the country-specific level. However, further research should focus on the responsiveness of the HeartQoL, the possible ceiling effect of the emotional subscale, construct validity and the minimal clinically important difference.