EQ-5D vision bolt-on in macular degeneration: associations with visual measures and effect on utility differences and cost-effectiveness of stereotactic radiotherapy

Summary

This study looks at how well a standard quality-of-life measure captures the effect of sight loss in people with wet age-related macular degeneration. The researchers used data from the STAR clinical trial to compare patients’ vision, reported quality of life and the costs of stereotactic radiotherapy alongside anti-VEGF treatment.

The study found that people reporting vision problems also had poorer vision and lower quality-of-life scores. Over four years, stereotactic radiotherapy was estimated to reduce healthcare costs by about £404 per patient and had a 65% probability of being cost-effective at a £20,000 per QALY threshold. However, adding a specific vision measure to the quality-of-life tool did not change the overall cost-effectiveness result.

Keywords: age-related macular degeneration, wet AMD, stereotactic radiotherapy, quality of life, cost-effectiveness, vision, anti-VEGF

Abstract

Background

The UK STAR trial [Stereotactic Radiotherapy (SRT) for neovascular age-related macular degeneration (nAMD)] compared 16-Gray SRT (n = 274) with double-masked sham SRT (n = 137) in participants with chronic active nAMD. SRT reduced intravitreal anti-vascular endothelial growth factor (VEGF) re-treatments over two years of pro re nata ranibizumab, followed by two years of routine care. However, this resulted in worse best-corrected visual acuity (BCVA) in Years 3 and 4. This paper describes: associations between the EQ-5D vision bolt-on and visual acuity and patient-reported outcome measures; the impact of SRT on utilities with and without vision bolt-on; how the vision bolt-on affects the cost-effectiveness of SRT plus anti-VEGF versus anti-VEGF alone.

Methods

Using data from the entire STAR trial cohort, we compared mean BCVA, EQ-5D-5L, and Visual Function Questionnaire-25 (VFQ-25) scores across the three levels of the EQ-5D vision bolt-on. We examined the relationship between BCVA and EQ-5D (with/without the bolt-on) and VFQ-25. An economic evaluation estimated the cost-effectiveness of SRT from a UK national health service perspective over two years and over four years. This used prospective data on EQ-5D-5L and eye-related direct healthcare use.

Results

Participants reporting vision problems on the bolt-on had significantly worse BCVA, EQ-5D-5L, and VFQ-25 scores than those who did not. EQ-5D utilities (with and without the bolt-on) increased with BCVA but showed weaker correlations than VFQ-25 composite scores. Quality-adjusted life years (QALYs) did not differ significantly between treatment groups, with or without the bolt-on. The economic evaluation suggested SRT would reduce healthcare costs by £404 (95% CI: -£1282 to £2092) per patient at a four-year time horizon. The probability of SRT plus anti-VEGF being cost-effective at a £20,000 per QALY threshold was 65% at a four-year time horizon. Sensitivity analyses confirmed the robustness of incorporating the vision bolt-on did not alter the cost-effectiveness conclusion.

Conclusions

Resource use data from the trial and routine follow-up could be used for future economic models. The vision bolt-on captured quality of life differences between participants but may not be sufficiently responsive to visual acuity decline in trials where only one eye is treated.

Trial registration

ISRCTN12884465, registration date 01/12/2014.