Clinically Meaningful Change Estimates for the National Eye Institute Visual Function Questionnaire-25 in Patients With Diabetic Macular Edema.

Abstract

Purpose: To derive estimates of clinically meaningful change (improvement) on the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) in patients with diabetic macular edema (DME) using anchor- and distribution-based methods.

Methods: In this exploratory post hoc analysis of data from the RIDE/RISE (NCT00473382/NCT00473330) clinical trials of ranibizumab for DME, the NEI VFQ-25 was completed at baseline and six, 12, 18, and 24 months. Anchor-based (≥5-, ≥10-, and ≥15-letter gain in best-corrected visual acuity [BCVA]) and distribution-based estimates were calculated. Subgroup analyses included outcomes when the study eye was the better- or worse-seeing eye.

Results: Baseline characteristics were balanced between the trials (RIDE, N = 382; RISE, N = 377). Anchor-based estimates of clinically meaningful improvement in composite scores (for ≥15-letter gain in BCVA) were 3.78 and 2.23 for RIDE and RISE, respectively. Estimates appeared similar for most subscales: near activities (4.11 and 3.31), distance activities (3.53 and 3.74), driving difficulties (5.15 and 3.15), and vision-specific dependency (4.70 and 1.83). Supportive distribution-based meaningful change composite score estimates also were similar between RIDE and RISE for values based on 0.5 standard deviation (9.85 and 9.70, respectively) or standard error of the mean (5.10 and 4.82, respectively).

Conclusions: These analyses suggest improvement of three to five points on the NEI VFQ-25 composite score and four individual subscales as clinically meaningful in patients with DME.

Translational relevance: This analysis supports considering these thresholds when assessing the clinical risk-benefit of DME treatment from the patient perspective using the NEI VFQ-25.