Which Questionnaire Should Be Used to Measure Quality-of-Life Utilities in Patients with Acute Leukemia? An Evaluation of the Validity and Interpretability of the EQ-5D-5L and Preference-Based Questionnaires Derived from the EORTC QLQ-C30.

OBJECTIVES: The aim of this study was to assess the validity and interpretability of different preference-based questionnaires (generic 5-level EuroQol five-dimensional questionnaire [EQ-5D-5L], cancer-specific Quality of Life Questionnaire Preference-Based Measure, and European Organization of Randomized Controlled Trials 8 Dimension [EORTC-8D]) in patients with acute leukemia. METHODS: Patients who participated in Hemato-Oncologie voor Volwassenen Nederland (HOVON - the Haemato Oncology Foundation for Adults in the Netherlands) clinical trials between 1999 and 2011 at a single hospital were invited to complete the questionnaires. Interpretability was evaluated by the frequency of incomplete data and highest and lowest possible scores. Content validity was evaluated by exploring the health-related quality-of-life domains included in the questionnaires. Construct validity was assessed using correlations with other quality-of-life scales (EQ-visual analogue scale score and global quality-of-life scale of the EORTC Quality of Life Questionnaire) and ability to distinguish between patients with different health statuses. RESULTS: Questionnaires were returned by 89% (111 of 125) of the patients. Six to seven respondents did not return full questionnaires. Perfect health on the EQ-5D-5L was reported by 32 respondents and many of them (N = 17) did report health problems on other questionnaires. All questionnaires were strongly correlated (range 0.61-0.78) with other quality-of-life scales and yielded substantially different utility values for patients with different health statuses. Nevertheless, the disease-specific preference-based questionnaires showed greater discriminatory power. CONCLUSIONS: Although the Quality of Life Questionnaire Preference-Based Measure and the EORTC-8D appear to have better validity, this study does not provide any strong evidence against the use of the EQ-5D-5L for measuring quality-of-life utilities in acute leukemia. However, our findings need to be confirmed in larger longitudinal studies.