Abstract 2650: Reliability and Validity of Retrospective Extraction of the ABCD2 Score From Medical Records
Background and Purpose: The ABCD2 score is increasingly used for risk stratification of TIA patients. Many of the studies assessing the utility of the ABCD2 score have retrospectively extracted the score from medical records, but the reliability of estimation based on chart review has not been reported. We sought to determine whether the ABCD2 score can be estimated retrospectively from medical records.
Methods: We compared ABCD2 scores that were prospectively determined by a board certified vascular neurologist to scores determined retrospectively from medical record review. All ED records and initial neurology consult resident notes were abstracted with explicit ABCD2 scoring redacted. ABCD2 scores were then estimated by two independent blinded trained raters using these records. Estimated component, total scores, and ABCD2 risk category (0-3, 4-5, 6-7), were compared both between raters and with the prospectively obtained scores. Reliability was assessed using unweighted kappa statistics.
Results: Records were analyzed for 55 consecutive TIA patients. For the two raters of retrospective ABCD2 scores, interrater reliability was good with 75% exact agreement in total score between raters (κ=0.68) and 84% agreement for ABCD2 category (κ=0.74). Interrater agreement on individual items was greatest for age and diabetes, and poorest for clinical features and duration. Retrospectively estimated total ABCD2 scores were identical to prospective scores in 52% of patients. Agreement between raters and the prospectively obtained score was >90% for age, blood pressure, and diabetes, but was only ∼70% for clinical features and duration. Retrospectively estimated ABCD2 category was identical to the prospective category in 64% of patients (Table). Dichotomizing at an ABCD2 score ≥4, retrospective assessment had a sensitivity of 83% (CI 70-95%) and specificity of 67% (CI 40-95%) compared to the prospective score.
Conclusions: The ABCD2 score can be abstracted from medical records with good interrater reliability but limited validity, which may lead to misclassification of risk category in over one-third of patients.
- © 2012 by American Heart Association, Inc.