Measuring quality of life at the end of life: Validation of the QUAL-E

Abstract

Objectives:To validate the QUAL-E, a new measure of quality of life at the end of life. Methods:We conducted a cross-sectional study to assess the instrument's psychometric properties, including the QUAL-E's associations with existing measures, evaluation of robustness across diverse sample groups, and stability over time. The study was conducted at the VA and Duke University Medical Centers, Durham, North Carolina, in 248 patients with stage IV cancer, congestive heart failure with ejection fraction ≤20%, chronic obstructive pulmonary disease with FEV 1≤ 1.0 l, or dialysis-dependent end stage renal disease. The main outcome measures included QUAL-E and five comparison measures: FACIT quality of life measure, Missoula-VITAS Quality of Life Index, FACIT-SP spirituality measures, Participatory Decision Making Scale (MOS), and Duke EPESE social support scales. Results:QUAL-E analyses confirmed a four-domain structure (25 items):life completion(α = 0.80),symptoms impact(α = 0.87),relationship with health care provider(α = 0.71), and preparation for end of life(α = 0.68). Convergent and discriminant validity were demonstrated with multiple comparison measures. Test–retest reliability assessment showed stable scores over a 1-week period. Significance of results:The QUAL-E, a brief measure of quality of life at the end of life, demonstrates acceptable validity and reliability, is easy to administer, performs consistently across diverse demographic and disease groups, and is acceptable to seriously ill patients. It is offered as a new instrument to assist in the evaluation of the quality and effectiveness of interventions targeting improved care at the end of life.