Estimating health related quality of life effects in vitiligo. Mapping EQ-5D-5 L utilities from vitiligo specific scales: VNS, VitiQoL and re-pigmentation measures using data from the HI-Light trial

Rabiah Begum; Ralph Crott; Reynaldo Martina; Eleni M Loizidou; Iftekhar Khan

doi:10.1186/s12955-023-02172-4

Estimating health related quality of life effects in vitiligo. Mapping EQ-5D-5 L utilities from vitiligo specific scales: VNS, VitiQoL and re-pigmentation measures using data from the HI-Light trial

Health Qual Life Outcomes. 2023 Aug 10;21(1):85. doi: 10.1186/s12955-023-02172-4.

Authors

Rabiah Begum¹, Ralph Crott², Reynaldo Martina³, Eleni M Loizidou⁴, Iftekhar Khan⁵

Affiliations

¹ Department of Population Health Sciences, University of Leicester, Leicester, UK. rk406@le.ac.uk.
² IRSS, Catholic University of Louvain, Brussels, 1200, Belgium.
³ Open University UK, Milton Keynes, UK.
⁴ Biobank.cy, Center of Excellence in Biobanking and Biomedical Research, University of Cyprus, Nicosia, Cyprus.
⁵ Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, UK.

Abstract

Background: Vitiligo is reported to affect 2% of the world's population and has a significant impact on health related quality of life (HRQoL). The relationship between HRQoL and clinical outcomes used in vitiligo require further examination. Mapping condition specific measures of HRQoL: vitiligo specific quality of life instrument (VitiQoL), vitiligo noticeability scale (VNS) and vitiligo re-pigmentation scores (RPS) to the EQ-5D have not yet been reported.

Methods: Data collected from a randomised clinical trial (HI-Light) in vitiligo was used to develop mapping algorithms for the EQ-5D-5 L and the relationship between HRQoL, clinical outcomes and EQ-5D were investigated. Two EQ-5D-5 L value sets (Van Hout and Alava) using linear and non-linear models were considered. Logistic regression models were used to model the probability of vitiligo noticeability (VNS) in terms of RPS, EQ-5D and VitiQoL scores.

Results: Mapping from RPS appeared to perform better followed by VNS for the Alava crosswalks using polynomial models: Mean observed vs. predicted utilities of 0.9008 (0.005) vs. 0.8984 (0.0004) were observed for RPS. For VNS, mean observed vs. predicted utilities of 0.9008 (0.005) vs. 0.8939 (0.0003) were observed. For VitiQoL, mean observed vs. predicted utilities of 0.9008 (0.005) vs. 0.8912 (0.0002) were observed. For patients with the least re-pigmentation (RPS < 25%), a Total VitiQoL score of about 20 points gives around an 18% chance of vitiligo being no longer or a lot less noticeable.

Conclusion: The algorithm based on RPS followed by VNS performed best. The relationship between effects from vitiligo specific HRQoL instruments and clinical RPS was established allowing for plausible clinically relevant differences to be identified, although further work is required in this area.

Keywords: Dermatology; EQ-5D; EuroQoL; Mapping; Re-pigmentation; VNS; VitiQoL; Vitiligo.

Publication types

Randomized Controlled Trial

MeSH terms

Algorithms
Humans
Logistic Models
Pigmentation
Quality of Life*
Surveys and Questionnaires
Vitiligo* / therapy