Abstract 131: Interrater Reliability of the ABCD2 Score
Background: The ABCD2 score is increasingly used for risk stratification of TIA patients, but little is known about the interrater reliability of the score.
Methods: Patients presenting to the emergency department with suspected TIA (symptom duration <24 hours) were prospectively evaluated. Only those asymptomatic at the time of enrollment were eligible. Patients verbally consented to questioning by multiple raters. We compared ABCD2 scores determined by raters of different medical specialties to the “gold standard” score of neurovascular attending physicians. Raters were given a worksheet with basic ABCD2 scoring instructions to complete for each subject; all scores were based on history obtained directly from the patient by each rater. Estimated component, total scores, and ABCD2 risk category (0-3, 4-5, 6-7) were compared both between raters and with the neurovascular attending score. Reliability was assessed using unweighted kappa statistics.
Results: A total of 46 patients were assessed, with each scored by a mean of 3.3 raters. In addition to the neurovascular attending, scores were generated by neurology junior (n=37) and senior residents (n=9), and internal medicine (n=36) and emergency medicine residents (n=36). Based on neurovascular attending scores, 35% of patients were categorized as low-risk (ABCD2 score 0-3), 50% as moderate risk (4-5), and 15% as high risk (6-7). Interrater reliability was limited for ABCD2 total score (κ=0.28) and category (κ=0.39). Interrater reliability of the component scores was near perfect for age (κ=1) and diabetes (κ=0.94) and substantial for blood pressure (κ=0.66), but only moderate for clinical features (κ=0.54) and duration (κ=0.59). Agreement between ABCD2 risk category scored by the neurovascular attending and that determined by other raters was as follows: 73% (95%CI:58-88%) for neurology junior residents, 89% (CI:63-100%) for neurology senior residents, 58% (CI:41-75%) for internal medicine residents, and 70% (CI:48-92%) for emergency medicine residents.
Conclusions: The interrater reliability of the ABCD2 score is poor. Clinical symptoms (C) and duration (D) displayed the greatest variability among ABCD2 components.
- © 2012 by American Heart Association, Inc.