Comparison of the measurement properties of EQ-5D-5L and SF-6Dv2 in Chinese patients on dialysis.

Background: Measuring health-related quality of life (HRQoL) in dialysis patients is essential for clinical assessment and economic evaluation. Despite the emergence and increasing use of updated instruments, evidence comparing their performance in Chinese dialysis patients remains limited. The aim of this study was to compare the measurement properties of the EQ-5D-5L and the SF-6Dv2 instruments in Chinese patients on dialysis and to provide a reference for future utility scale choice for Chinese dialysis patients.

Methods: Data were obtained using Wen Juan Xing questionnaire from dialysis patients during November 2023 to January 2024 in hospitals in China. The questionnaire included the EQ-5D-5L, SF-6Dv2, the kidney disease quality of life instrument (KDQOL-36), clinical and socio-demographic characteristics. The agreement of utility scores was assessed using intra class correlation coefficients (ICC) and Bland-Altman plots. The construct validity was evaluated using Spearman's correlation coefficient. The known group validity was evaluated by comparing the scores among patients with different health states, and sensitivity was compared using relative efficiency and the effect size.

Results: A total of 378 patients (male, 49.5%; mean age, 49.1 years) were included in this study. The ICC between EQ-5D-5L and SF-6Dv2 utility values was 0.639. The correlation between the two scales was strong (0.767). Both scales showed known groups validity, although the SF-6Dv2 was more sensitive. The differences in the SF-6Dv2 scores for patients in better and worse health state were greater than those measured by the EQ-5D-5L scores.

Conclusions: Both EQ-5D-5L and SF-6Dv2 instruments are valid for dialysis patients. However, the two scales cannot be used interchangeably, and it appears that the SF-6Dv2 was more sensitive in capturing health state differences for dialysis patients in China.