Ophthalmology · Medical Literature
EQ-5D vision bolt-on in macular degeneration: associations with visual measures and effect on utility differences and cost-effectiveness of stereotactic radiotherapy.
Abstract
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. 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. 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. 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. ISRCTN12884465, registration date 01/12/2014.
Clinical relevance
Does adding an EQ-5D vision bolt-on to the standard EQ-5D-5L instrument improve capture of health-related quality-of-life differences in patients with neovascular age-related macular degeneration (nAMD) treated with stereotactic radiotherapy plus anti-VEGF versus anti-VEGF alone, and does its inclusion materially alter the cost-effectiveness conclusion? __SNAPSHOT__ {"studyDesign":"Pre-specified health economic and patient-reported outcome substudy embedded within the UK STAR randomized, double-masked, sham-controlled device trial","setting":"30 UK hospitals with dedicated national SRT treatment centres; UK NHS perspective for economic evaluation","sampleSize":"n=411 (SRT: n=274; sham SRT: n=137), reflecting the entire STAR trial cohort","population":"Adults aged ≥50 years with chronic active nAMD who had received ≥3 prior anti-VEGF injections, including ≥1 in the preceding 4 months","intervention":"Single-fraction 16-Gray stereotactic radiotherapy delivered by robotically controlled device plus pro re nata (PRN) ranibizumab over 2 years, followed by 2 years of routine care","comparator":"Double-masked sham SRT plus pro re nata ranibizumab over 2 years, followed by 2 years of routine care","primaryOutcome":"Associations between EQ-5D vision bolt-on levels and BCVA/VFQ-25; impact of SRT on EQ-5D-derived utilities with and without the vision bolt-on; cost-effectiveness of SRT plus anti-VEGF versus anti-VEGF alone at 2- and 4-year time horizons","followUp":"4 years (2 years of PRN ranibizumab plus 2 years of routine care follow-up)","fundingSource":"UK Medical Research Council (MRC) and National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation Programme (joint government funding); Oraya/Carl Zeiss provided free use of the SRT device but had no role in analysis, interpretation, or publication"}
Key findings
Participants reporting vision problems on the EQ-5D vision bolt-on had significantly worse mean BCVA, EQ-5D-5L, and VFQ-25 scores than those who did not, establishing construct validity of the bolt-on in this nAMD population. At the 4-year time horizon, the economic evaluation estimated that SRT plus anti-VEGF would reduce total healthcare costs by £404 per patient compared with anti-VEGF alone (95% CI: −£1,282 to £2,092), indicating cost savings that do not achieve statistical significance and span a range inclusive of net costs. The probability that SRT plus anti-VEGF is cost-effective at the standard UK NICE willingness-to-pay threshold of £20,000 per QALY was 65% at the 4-year time horizon. QALY estimates were derived using EQ-5D-5L utilities calculated as area under the annual health utility curve; incremental QALYs and the ICER were not reported numerically in the abstract. Sensitivity analyses incorporating vision bolt-on utilities did not alter the cost-effectiveness conclusion. The 4-year extended follow-up showed worse BCVA in the SRT group compared with sham (p<0.01; eight-letter deficit), yet VFQ-25 and EQ-5D-5L responses remained comparable between groups during that period — a clinically important disconnect between objective visual acuity and patient-reported outcomes. No additional adverse event data beyond those reported in the primary STAR trial (which noted more cardiac adverse events in the SRT group: 14% vs. 8%) were reported in this substudy abstract.
Practice implications
This study established that the EQ-5D vision bolt-on is a valid instrument for discriminating health-related quality-of-life levels in nAMD — participants with worse vision problems on the bolt-on had measurably worse BCVA and vision-specific PROs. However, the bolt-on did not alter the overall cost-effectiveness conclusion: adding the vision dimension to the utility instrument left unchanged the finding that SRT plus anti-VEGF has a 65% probability of being cost-effective at the £20,000/QALY threshold over 4 years, with a point estimate suggesting modest cost savings. A critically important finding for interpretation is the disconnect between clinical and patient-reported measures: despite an 8-letter BCVA deficit in the SRT arm at years 3–4, EQ-5D-5L and VFQ-25 responses remained comparable between groups. This raises a fundamental methodological concern about the sensitivity of the standard EQ-5D — and even the vision bolt-on — to monocular or modest unilateral visual acuity changes, as the trial treated only one eye. Findings are directly applicable to patients with chronic, pretreated active nAMD aged ≥50 years in a UK NHS setting receiving ranibizumab. Patients receiving newer anti-VEGF agents (aflibercept, faricimab, brolucizumab), treatment-naïve patients, and those with other forms of AMD were not adequately represented. The 65% cost-effectiveness probability at £20,000/QALY represents meaningful but not conclusive evidence; routine adoption of SRT on cost-effectiveness grounds alone would be premature without further confirmatory data, particularly given the BCVA signal of harm at years 3–4. This analysis is based on the abstract only; full methodological details, including ICER point estimates and complete QALY data, are available only in the full publication. __LIMITATIONS__ Only the abstract was available for this summary; quantitative outputs such as the ICER, incremental QALY gain, and full probabilistic sensitivity analysis results are not reported here.,The vision bolt-on may lack sufficient responsiveness to unilateral or modest visual acuity changes: a clinically significant 8-letter BCVA deficit in the SRT arm at years 3–4 was not reflected in EQ-5D or VFQ-25 group differences, limiting the instrument's ability to capture the full HRQoL burden of vision loss in monocular trials.,The trial enrolled only participants treated with ranibizumab under a PRN protocol; applicability to treat-and-extend or modern anti-VEGF agents (faricimab, aflibercept 8 mg) is uncertain.,The cost-effectiveness probability of 65% at £20,000/QALY reflects considerable uncertainty; the 95% CI for cost savings spans from net savings (−£1,282) to net costs (+£2,092), and the ICER was not reported.,The 4-year follow-up period may be insufficient to model long-term disease trajectory, radiation-related toxicity (e.g., retinal microvascular abnormalities), and downstream costs.,Generalizability is limited to a UK NHS setting; cost structures, drug pricing, and willingness-to-pay thresholds differ internationally.,Although double-masked for the clinical trial, the health economic analysis is inherently observational in its resource utilization components and is subject to missing data and COVID-19 pandemic disruptions during the trial period.,Industry (Oraya/Carl Zeiss) provided in-kind support (device access), which may introduce implicit bias in favor of demonstrating device utility, even though the sponsor had no role in manuscript preparation. __BOTTOM_LINE_CATEGORY__ promising_but_preliminary __BOTTOM_LINE__ In patients with chronic active nAMD, adding an EQ-5D vision bolt-on validates sensitivity to vision-related quality-of-life differences but does not change the cost-effectiveness conclusion: SRT plus anti-VEGF has a 65% probability of being cost-effective at the UK £20,000/QALY threshold at 4 years, with modest point-estimate cost savings. However, the failure of the vision bolt-on to capture the 8-letter BCVA deficit observed at years 3–4 underscores a critical limitation of generic utility instruments in monocular ophthalmic trials, and the broader safety-efficacy tradeoff of SRT warrants caution before clinical adoption.