Discrepancies in automated, electronic medical record-based CHA2DS2-VASc scores and clinician assessment for atrial fibrillation patients

Background Clinical decision support tools for atrial fibrillation (AF) should include CHA 2 DS 2 - VASc scores to guide oral anticoagulant (OAC) treatment. Objective We compared automated, electronic medical record (EMR) generated CHA 2 DS 2 - VASc scores to clinician-documented scores, and report the resulting proportions of patients in the OAC treatment group. Methods Patients were included if they had both a clinician documented and EMR-generated CHA 2 DS 2 -VASc score on the same day. EMR scores were based on billing codes, left ventricular ejection fraction from echocardiograms, and demographics; documented scores were identified using natural language processing. Patients were deemed “re-classified” if the EMR score was ≥2 but the documented score was <2, and vice versa. For the overall cohort and subgroups (sex and age group), we compared mean scores using paired t-tests and re-classification rates using chi-squared tests. Results Among 5,767 patients, the mean scores were higher using EMR compared to documented scores (4.05 [SD 2.1] versus 3.13 [SD 1.8]; p<0.01) for the full cohort, and all subgroups (p<0.01 for all comparisons). If EMR scores were used to determine OAC treatment instead of documented scores, 8.3% (n=479, p<0.01) of patients would be re-classified, with 7.2% moving into and 1.1% moving out of the treatment group. Among 2,322 women, 4.7% (n=109, p<0.01) would be re-classified, with 4.1% into and 0.7% out of the treatment group. Among 3,445 men, 10.7% (n=370, p<0.01) would be re-classified, with 9.2% into and 1.5% out of the treatment group. Among 2,060 patients <65 years old, 18.1% (n=372, p<0.01) would be re-classified, with 15.8% into and 2.3% out of the treatment group. Among 1,877 patients 65-74 years old, 5.4% (n=101, p<0.01) would be re-classified, with 4.4% into and 1.0% out of the treatment group. Among 1,830 patients ≥75 years old, <1% would move into to the treatment group and none would move out of the treatment group. Conclusions EMR-based CHA 2 DS 2 -VASc scores were, on average, almost a full point higher than the clinician-documented scores. Using EMR scores in lieu of documented scores would result in a significant proportion of patients moving into the treatment group, with the highest re-classifications rates in men and patients <65 years old.