A risk score for the prediction of advanced age-related macular degeneration: development and validation in 2 prospective cohorts

Abstract

Purpose: To develop a clinical eye-specific prediction model for advanced age-related macular degeneration (AMD).

Design: The Age-Related Eye Disease Study (AREDS) cohort followed up for 8 years served as the training dataset, and the Blue Mountains Eye Study (BMES) cohort followed up for 10 years served as the validation dataset.

Participants: A total of 4507 AREDS participants (contributing 1185 affected vs. 6992 unaffected eyes) and 2169 BMES participants (contributing 69 affected vs. 3694 unaffected eyes).

Methods: Using Bayes' theorem in a logistic model, we used 8 baseline predictors-age, sex, education level, race, smoking status, and presence of pigment abnormality, soft drusen, and maximum drusen size-to devise and validate a macular risk scoring system (MRSS). We assessed the performance of the MRSS by calculating sensitivity, specificity, and the area under the receiver operating characteristic curve (i.e., c-index).

Main outcome measures: Advanced AMD.

Results: The internally validated c-indexAREDS (0.88; 95% confidence interval, 0.87-0.89) and the externally validated c-indexBMES (0.91; 95% confidence interval, 0.88-0.95) suggested excellent performance of the MRSS. The sensitivity and specificity at the optimal macular risk score cutoff point of 0 were 87.6% and 73.6%, respectively. An application for the iPhone and iPad also was developed as a practical tool for the MRSS.

Conclusions: The MRSS was developed and validated to provide satisfactory accuracy and generalizability. It may be used to screen patients at risk of developing advanced AMD.