Use of Diagnostic Codes for Primary Open-Angle Glaucoma Polygenic Risk Score Construction in Electronic Health Record-linked Biobanks

Abstract

Purpose Polygenic risk scores (PRSs) likely predict risk and prognosis of glaucoma. We compared the PRS performance for primary open-angle glaucoma (POAG), defined using International Classification of Diseases (ICD) codes versus manual medical record review. Design Retrospective cohort study Methods We identified POAG cases in Mount Sinai BioMe and Mass General Brigham (MGB) biobank using ICD codes. We confirmed POAG based on optical coherence tomograms and visual fields. In a separate 5% sample, the absence of POAG was confirmed with intraocular pressure and cup-disc ratio criteria. We used genotype data and either self-reported glaucoma diagnoses or ICD-10 codes for glaucoma diagnoses from the UK Biobank and the lassosum method to compute a genome-wide POAG PRS. We compared the area under the curve (AUC) for POAG prediction based on ICD codes versus medical records. Results We reviewed 804 of 996 BioMe and 367 of 1,006 MGB ICD-identified cases. In BioMe and MGB, respectively: positive predictive value was 53% and 55%; negative predictive value was 96% and 97%; sensitivity was 97% and 97%; and specificity was 44% and 53%. Adjusted PRS AUCs for POAG using ICD codes vs. manual record review in BioMe were not statistically different (p≥0.21) by ancestry: 0.77 vs. 0.75 for African, 0.80 vs. 0.80 for Hispanic, and 0.81 vs. 0.81 for European. Results were similar in MGB (p≥0.18): 0.72 vs. 0.80 for African, 0.83 vs. 0.86 for Hispanic, and 0.74 vs. 0.73 for European. Conclusions A POAG PRS performed similarly using either manual review or ICD codes in two EHR-linked biobanks; manual assessment of glaucoma status might be unnecessary for some PRS studies. However, caution should be exercised with using ICD codes for glaucoma diagnosis given their low specificity (44-53%) for manually confirmed cases of glaucoma.