Evaluating the Relationship Between Visual Acuity and Utilities in Patients With Diabetic Macular Edema Enrolled in Intravitreal Aflibercept Studies.

ABSTRACT

Purpose: The purpose of this study was to explore the relationship between visual acuity and utility (health-related quality of life) in diabetic macular edema (DME) using intravitreal aflibercept data. Methods: The relationship between visual acuity in the best-seeing eye (BSE) and worse-seeing eye (WSE) and utility was explored using ordinary least squares (OLS) and random-effects models adjusted for different covariates (age, age2, sex, body mass index, smoking status, glycated hemoglobin, diabetes severity, comorbidities, and geographic region). Utility was measured using the EuroQoL-five dimensions questionnaire (EQ-5D) and Visual Functioning Questionnaire-Utility Index (VFQ-UI). For each model, coefficients (R2) were reported, and WSE/BSE was expressed as the ratio of coefficients (OLS models). Models were independent of treatment effects, and outcomes from all time points (up to week 100) were included where available. Results: Data from 1320 patients with DME were analyzed. In all models, the association between visual acuity (BSE > WSE) was stronger with VFQ-UI- than EQ-5D-derived utilities. The estimated relationship between VFQ-UI and visual acuity in the BSE and WSE was robust, even with an increasing number of covariates. WSE/BSE coefficient ratios were similar across VFQ-UI OLS models (32%) compared with EQ-5D models (41%-48%). Actual (unadjusted) versus predicted data plots also showed a better fit with VFQ-UI- than EQ-5D-derived utilities. Conclusions: These analyses show that VFQ-UI was more sensitive than EQ-5D-derived utilities for measuring the impact of visual acuity in the BSE and WSE. Visual acuity in the BSE was a major contributor to utility, but WSE is also important though to a lesser degree as shown by the coefficient ratios. These new data will be useful for health technology assessments in DME, where utilities data are lacking.