Validation and comparison of EQ-5D-5L and SF-6Dv1 in myopic patients requiring corneal refractive surgery in China

Different health-related quality of life scales are suitable for various populations and scenarios; hence, the selection of measurement tools must be based on research objectives and focal points. To facilitate the choice between EQ-5D-5L and SF-6Dv1 in clinical and economic research of myopic patients undergoing corneal refractive surgery, the study aims to assess and compare EQ-5D-5L and SF-6Dv1 among the patients in China.

A total of 411 participants with a mean age of 25.6 years were recruited. Information collected including demographic characteristics, EQ-5D-5L and SF-6Dv1. The ceiling effect was evaluated by calculating the proportion of participants who reported the best possible health states. Agreement between EQ-5D-5L and SF-6Dv1 health utility scores (HUSs) was tested using intraclass correlation coefficient (ICC) and Bland-Altman plot. Convergent validity of EQ-5D-5L and SF-6Dv1 HUSs was evaluated using the Spearman correlation coefficient (r) with VF-14 as a calibration standard.

Ceiling effects were 75.2% and 40.4% for EQ-5D-5L and SF-6Dv1, respectively. ICC between the two HUSs was 0.611 (average-measure). Bland-Altman plots showed that the agreement varied across different HUS segments. Correlation between EQ-5D-5L HUS and VF-14 (r = 0.363) was higher than that between SF-6Dv1 HUS and VF-14 (r = 0.226). EQ-5D-5L and SF-6Dv1 HUSs can only distinguish one clinical condition (i.e., chronic pain symptom); but they can identify health differences across all self-reported known-groups. EQ-5D-5L HUS had greater sensitivity; but SF-6Dv1 HUS was more responsive at follow-ups.

EQ-5D-5L and SF-6Dv1 HUS cannot be used interchangeably in myopic patients undergoing corneal refractive surgery. It appears that EQ-5D-5L HUS performs better in terms of convergent validity and sensitivity; but SF-6Dv1 HUS is more responsive.