Reliability and validity of EuroQol-5 Dimensions-5 Levels in patients with haematologic malignancies: a cross-sectional study in China.

[OBJECTIVES] Robust assessment of health-related quality of life (HRQoL) is essential for evaluating the disease burden in patients with haematologic malignancies. This study examined the performance of the EuroQol-5 Dimensions-5 Levels (EQ-5D) instrument in patients with multiple myeloma (MM), acute leukaemia (AL) and lymphoma using time trade-off (TTO)-elicited utility scores as the reference, and explored factors contributing to discrepancies between EQ-5D and TTO utilities.

[DESIGN] We performed a cross-sectional observational study using EQ-5D and TTO to assess HRQoL.

[SETTING] A leading tertiary care hospital in China.

[PARTICIPANTS] 158 patients consecutively admitted to hospital for MM (n=50), AL (n=63) and lymphoma (n=45) between January and August 2024.

[OUTCOME MEASURES] The primary outcome was the EQ-5D performance in terms of internal consistency (Cronbach's α), criterion validity (Spearman's correlation with TTO), and structural validity (exploratory factor analysis). The secondary outcome was the patient characteristics associated with discrepancies between EQ-5D and TTO utilities.

[RESULTS] TTO utility scores were highest in AL (0.798), followed by lymphoma (0.755) and MM (0.693). EQ-5D utility values were consistently higher than TTO across all groups. Among the three groups, EQ-5D demonstrated the best psychometric performance in patients with MM, with excellent internal consistency (Cronbach's α=0.899), strongest correlation with TTO (r=0.538, p<0.001) and high structural validity. By contrast, EQ-5D showed moderate validity in AL (r=0.386, p=0.002) and poor validity in lymphoma (r=0.230, p=0.129). In patients with AL, chronic kidney failure was significantly associated with greater TTO-EQ-5D utility discrepancy (coefficient=0.213, p=0.035).

[CONCLUSIONS] EQ-5D performed well in patients with MM, supporting its use in this population. In patients with AL, adjustments for clinical characteristics such as chronic kidney failure may improve the accuracy of EQ-5D utility values. The poor psychometric performance of EQ-5D in patients with lymphoma raises concerns about its appropriateness as a standalone instrument for HRQoL.