Minimal clinically important difference of EQ-5D-5L, SF-6Dv2, and QLU-C10D in hematologic malignancy patients in China

Abstract Background To assess the minimum clinically important difference (MCID) of the EuroQol five-dimensional five-level (EQ-5D-5L), Short Form Six-Dimensional version 2 (SF-6Dv2), and Quality of Life Utility-Core 10 Dimensions (QLU-C10D) in Chinese patients with hematologic malignancies. Methods Longitudinal data were collected from lymphoma and multiple myeloma patients treated at a tertiary hospital in Shanghai, China. Baseline surveys were conducted in 2022, with follow-ups in 2023 at 3- to 6-month intervals. A total of 200 lymphoma and 139 multiple myeloma patients were enrolled, with 78 and 89 patients completing follow-up. HRQoL was assessed by EQ-5D-5L, SF-6Dv2, and EORTC QLQ-C30 (including QLU-C10D) questionnaires. We estimated MCID values using three methods: (1) anchor-based, using changes in EORTC QLQ-C30 total score and clinical indicators (PET-CT or M protein levels) as benchmarks; (2) distribution-based, calculating MCID using half of the baseline standard deviation (SD) and the standard error of measurement (SEM); and (3) instrument-defined, based on average score changes associated with single-level transitions in health states. Results Averaging the MCID values from the three calculation methods, the mean values for EQ-5D-5L, SF-6Dv2, and QLU-C10D were 0.070, 0.078, 0.044 for lymphoma patients, and 0.075, 0.087, 0.044 for multiple myeloma patients. The average MCID values from two anchors were 0.064, 0.077, 0.046 (lymphoma patients) and 0.074, 0.091, 0.056 (multiple myeloma patients). The mean distribution-based MCID values, derived from half the SD and the SEM were higher, with the values of 0.086 (EQ-5D-5L), 0.080 (SF-6Dv2), 0.052 (QLU-C10D) for lymphoma patients and 0.097, 0.091, 0.056 for multiple myeloma patients. The lowest mean MCID values, determined using instrument-defined estimates, were 0.061 (EQ-5D-5L) and 0.033 (QLU-C10D) for lymphoma patients, and 0.054 (EQ-5D-5L) and 0.021 (QLU-C10D) for multiple myeloma patients. Conclusion This study provided the MCID estimates for EQ-5D-5L, SF-6Dv2, and QLU-C10D in Chinese patients with lymphoma and multiple myeloma.