. Author manuscript; available in PMC: 2014 Sep 1.

Published in final edited form as: J Thromb Haemost. 2013 Sep;11(9):1663–1668. doi: 10.1111/jth.12332

Table 2. 2×2 analysis of the predictive value of a ISTH BAT score of 12 and over in predicting the presence of a platelet defect on lumiaggregometry.

ISTH BAT score of 12 represents the 50^th centile in all patients studied. Sensitivity, specificity, positive predictive value and negative predictive value are shown. Kappa statistic for concordance = −0.04 (95% CI −0.26 to 0.18), demonstrating a lack of significance.

	Defect present on lumiaggregometry	Defect absent on lumiaggregometry
BAT score ≥ 12	20	20	Positive predictive value = 50%
BAT score < 12	21	18	Negative predictive value = 54%
	Sensitivity = 49%	Specificity = 53%