Validity and reliability of the EQ-5D-5 L in family caregivers of leukemia patients

Purpose: This study aimed to test the validity and reliability of the five-level EuroQol five-dimensional (EQ-5D-5 L) instrument in family caregivers (FCs) of leukemia patients in Heilongjiang of China. Methods: A cross-sectional survey was conducted on 298 family caregivers (FCs) of leukemia patients from three major cancer centers in the capital city of Heilongjiang province of China. Their dimensional scores of the EQ-5D-5 L were compared with those of the WHOQOL-BREF to test the convergent validity (constructs measuring the same concept) and divergent validity (constructs measuring different concepts) of the EQ-5D-5 L. Repeated surveys were conducted on 271 participants to determine the test-retest reliability of the EQ-5D-5 L. Results: The four physical dimensions (mobility, self-care, usual activities, and pain/discomfort) of the EQ-5D-5 L had moderate or high correlations with the physical health domain of the WHOQOL-BREF, with a correlation coefficient (r) ranging from 0.459 to 0.559. The anxiety/depression dimension of the EQ-5D-5 L had a high correlation (r = 0.667) with the psychological domain of the WHOQOL-BREF. By contrast, lower but still significant physical-to-psychological correlations were found between the two instruments (r ranging from 0.219 to 0.396). In addition, the EQ-5D-5 L dimensional scores showed no or weak correlations with the environment and social domains of the WHOQOL-BREF (r ranging from 0.016 to 0.207). High test-retest reliability (> 0.7) was evident. Conclusion: The Chinese version of the EQ-5D-5 L has satisfactory reliability and validity in FCs of leukemia patients. It can be used to elicit utility of health-related quality of life in FCs of leukemia.