ABCD2, risk prediction, stroke, TIA
Purpose: The ABCD2 clinical prediction rule (CPR) is designed to predict early risk of stroke after transient ischaemic attack (TIA). The purpose of this systematic review with meta-analysis is to determine the predictive value of the ABCD2 at 7 and 90 days across three strata of risk. Methods: A systematic literature search was conducted to identify studies that validated the ABCD2. The derived rule was used as a predictive model and applied to subsequent validation studies. Comparisons were made between observed and predicted number of strokes stratified by risk group, low (0-3 points), moderate (4-5 points) and high (6-7 points). Pooled results are presented as risk ratios (RRs) with 95% confidence intervals, in terms of over-prediction (RR>1) or under-prediction (RR<1) of stroke at 7 and 90 days. Results: We include 16 validation studies. Fourteen studies report 7 day stroke risk (n=6282, 388 strokes). The ABCD2 rule correctly predicts occurrence of stroke at 7 days across all three risk strata: low, (RR 0.86, 95%CI(0.47-1.58), I2=16%); moderate, (RR 0.99, 95%CI(0.67-1.47), I2=68%); high, (RR 0.84, 95%CI(0.6-1.19), I2=46%). Eleven studies report 90 day stroke risk (n=6304). There is a non-significant trend towards over prediction of stroke in all risk categories at 90 days. There are 426 strokes observed in contrast to a predicted 626 strokes. As the trichotomised ABCD2 score increases, the risk of stroke increases (p<0.01). There is no evidence of publication bias in these studies (p>0.05). Conclusion: The ABCD2 is a useful CPR, particularly in relation to 7 day risk of stroke.
Medicine and Health Sciences
Galvin R, Geraghty C, Motterlini N, Dimitrov BD, Fahey T. Prognostic value of the ABCD2 clinical prediction rule: a systematic review and meta-analysis. Family Practice. 2010;0:1-11.