Health-related quality of life in patients with a left ventricular assist device (QOLVAD) questionnaire : Initial psychometrics of a new instrument

Background
Patients with a left ventricular assist device are a unique and growing population who deserve their own valid, reliable instrument for health-related quality of life.

Objective
We developed and tested the Health-Related Quality of Life with a Left Ventricular Assist Device (QOLVAD) questionnaire.

Methods
In a prospective, descriptive study, patients from 7 sites completed the QOLVAD and comparator questionnaires. Construct validity was tested using confirmatory factor analysis. Convergent validity was tested using correlations of QOLVAD scores to well-established measures of subjective health status, depression, anxiety, and meaning/faith. Reliability and test-retest reliability were quantified.

Results
Patients (n = 213) were 58.7 ± 13.9 years old; 81.0% were male, 73.7% were White, and 48.0% had bridge to transplant. Questionnaires were completed at a median time of 44 weeks post ventricular assist device. The 5 QOLVAD domains had acceptable construct validity (root mean square error of approximation = 0.064, comparative and Tucker-Lewis fit indices > 0.90, weighted root mean square residual = 0.95). The total score and domain-specific scores were significantly correlated with the instruments to which they were compared. Internal consistency reliability was acceptable for all subscales (α = .79–.83) except the cognitive domain (α = .66). Unidimensional reliability for the total score was acceptable (α = .93), as was factor determinacy for multidimensional reliability (0.95). Total test-retest reliability was 0.875 (P < .001).

Conclusion
Our analysis provided initial support for validity and reliability of the QOLVAD for total score, physical, emotional, social, and meaning/spiritual domains. The QOLVAD has potential in research and clinical settings to guide decision making and referrals; further studies are needed.