A comparison of measurement properties between UK SF-6D and English EQ-5D-5L and Thai EQ-5D-5L value sets in general Thai population

ABSTRACT

Background

Evidence is limited for comparative psychometric properties between EQ-5D-5L and SF-6D. Therefore, this study compared psychometric properties between those instruments using value sets from Thailand, England, and the UK in the general Thai population.

Methods

A total of 1,200 participants were recruited. The agreement level was evaluated using intraclass correlation coefficients (ICCs) and Bland–Altman plots. Convergent validity with SF-12v2 was assessed by Spearman’s rho correlations. Known-group validity compared discriminant activity and sensitivity between groups. Responsiveness was assessed using standardized effect sizes (SES) and standardized response mean (SRM).

Results

Agreement between SF-6D and Thai (ICCs = 0.51) and English (ICCs = 0.52) EQ-5D-5L index scores was good. The physical functioning demonstrated moderate to strong and moderate correlations with Thai (r = 0.50) and English (r = 0.46) EQ-5D-5L index scores, whereas SF-6D index scores strongly correlated with role emotion (r = 0.81). EQ-5D-5L was better than SF-6D at discrimination and sensitivity for gender, age, education level, household income, and number of diseases. The SF-6D was more responsive than the EQ-5D-5L for the worsened group.

Conclusion

Both SF-6D and EQ-5D-5L are valid among the general Thai population. Further studies should reinvestigate responsiveness and determine their impacts on economic analyses among patient groups.

KEYWORDS:

• psychometric properties
• EQ-5D-5L
• SF-6D
• general population
• health-related quality of life

Acknowledgments

This work was financially supported by the Research Grant of Burapha University through the National Research Council of Thailand (Grant No. Rx2/2562). However, the results and opinions in this report have not been endorsed by the above funding agency or elsewhere. I would like to express my gratitude to all study samples from the provinces of Nakhon-Srithammarat, Khon-Kaen, Chonburi, Chiang-Mai, and Bangkok in Thailand. Special thanks to all trained interviewers for assistance with the interview process.

Supplementary material

Supplemental data for this article can be accessed here.

Ethical approval

This work was approved by the Burapha University Institutional Review Board (BUU-IRB): 108/2562 before the study commenced.

Consent to participate

The written consent form was obtained from each study subject before the study commenced; however, they were informed to be able to withdraw from this study at any time if they felt uncomfortable.

Authors’ contributions

Krittaphas Kangwanrattanakul (KK) was only involved in conception, study design, data collection, data analyses, interpretation, drafting, and final approval of this manuscript.

Availability of data and material

The data analyzed and reported in this manuscript are not available for public sharing.

Consent for publication

The author has approved this manuscript and agrees with submission to Expert Review of Pharmacoeconomics and Outcome Research.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewers disclosure

Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.

Additional information

Funding

This work was part of the project titled: “Psychometric properties comparison between EQ-5D-5L and EQ-5D-3L in the general Thai population”, which was financially supported by the Research Grant of Burapha University through the National Research Council of Thailand under Grant No. Rx2/2562.