The Kansas City Cardiomyopathy Questionnaire (KCCQ) -: A new disease-specific quality of life measure for patients with chronic heart failure psychometric evaluation of the German version

Patients' health-related quality of life is increasingly being included as an additional endpoint when evaluating the treatment of chronic heart failure. Although generic self-report instruments measuring health-related quality of life are available, there is a lack of disease-specific instruments covering various dimensions of quality of life with high reliability, validity and sensitivity to chance. Thus, the aim of the present study was to evaluate the German version of a new heart failure-specific quality of life measure, the Kansas City Cardiomyopathy Questionnaire (KCCQ). The sample consisted of 233 consecutively recruited outpatients of a university department in Germany. Test-retest-reliability was high (intraclass correlation coefficient 0.93 for both the Functional State and the Clinical Summary total scores). Construct validity was demonstrated with strong correlations to respective subscales of the SF-36. Known groups validity was shown by both statistically and clinically significant differences between NYHA classes. The examination of sensitivity to change yielded promising results. The questionnaire was well accepted by the participating patients. The KCCQ proved to be a reliable and valid self-report instrument for measuring disease-specific quality of life in chronic heart failure.