Health-Related Quality of Life in Patients With Ventricular Assist Device: Psychometric Evaluation of the German Version of the Quality of Life With a Ventricular Assist Device Questionnaire.

BACKGROUND:Ventricular assist device (VAD) implantation has become an alternative treatment for patients with end-stage heart failure. In Germany, valid and reliable instruments to assess health-related quality of life in patients with VAD are lacking. OBJECTIVE:The aim of this study was to present the psychometric validation of the German version of the Quality of Life with a Ventricular Assist Device questionnaire. METHODS:In a multicenter, cross-sectional study, 393 participants (mean age, 58.3 years; 85.8% male, 60.3% bridge to transplant, and 72.8% living with VAD for ≤2 years) completed the German Quality of Life with a Ventricular Assist Device questionnaire of physical, emotional, social, cognitive, and meaning/spiritual domains. Item and confirmatory factor analyses were conducted to test item difficulty and discrimination and the underlying structure, respectively. To examine internal consistency, Cronbach α was assessed. Convergent construct validity was tested using the Kansas City Cardiomyopathy Questionnaire and the Patient Health Questionnaire-9. Readability was examined using Flesch Reading Ease index and Vienna Factual Text Formula. RESULTS:The Quality of Life with a Ventricular Assist Device showed reasonable item difficulty (Ptotal = .67) and mostly moderate to high discriminatory power (rit > 0.30). In confirmatory factor analysis, root-mean-square error of approximation (0.07) was acceptable for model fit, but no other indices. Acceptable internal consistency was found (α ≥ 0.79), with the exception of the cognitive domain (α = 0.58). The overall questionnaire and single domains demonstrated convergent validity (r ≥ 0.45, P < .001). The questionnaire showed adequate readability (Flesch Reading Ease, 64.11; Vienna Factual Text Formula, 6.91). CONCLUSION:Findings indicate a promising standardized clinical instrument to assess health-related quality of life in patients with VAD.