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.

Abstract

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. 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. 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. 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). Findings indicate a promising standardized clinical instrument to assess health-related quality of life in patients with VAD.