May 2020

Assessing the accuracy of a large observational registry of neovascular age-related macular degeneration

Vuong Nguyen, King Fai Calvin Leung, Chu Luan Nguyen, David Squirrell, Rohan Essex, Jennifer Arnold, Stephanie Young, Daniel Barthelmes, Mark Gillies, Fight Retinal Blindness! Study Group


Purpose: To evaluate the accuracy of an observational database that tracks real-world treatment outcomes for neovascular age-related macular degeneration.

Methods: We audited 245 randomly sampled eyes from 189 patients with 3,356 visits from 11 doctors in the Fight Retinal Blindness!

Database: Sex, birth year, previous treatments received, treatment, and visual acuity were validated against the clinical notes. Error rates, the proportion of missed visits (the number of visits present in the patient record but not entered into Fight Retinal Blindness!), the level of agreement using Cohen’s kappa (κ) and intraclass correlation coefficients, and positive and negative predictive values were calculated. A visual acuity error was defined as an absolute difference of ≥5 letters.

Results: The overall error rate was 3.5% (95% confidence interval: 3.1-3.9). The error rate for visual acuity was 5.1% (95% confidence interval: 4.2-5.9) and 95%). The rate of missed visits was high, possibly due to the high burden of retrospective data entry or patients switching practitioners during treatment.