Table 2. Predictive values for the identification of patients within 4.5 hours of symptom onset.

Rating method	Classification		Sensitivity (95% CI)	Specificity (95% CI)	PPV (95% CI)	NPV (95% CI)	Accuracy (95% CI)
	FLAIR-negative	FLAIR-positive
Model 1: visual rating (‘liberal')	No lesions	‘Subtle' and ‘obvious' lesions	0.58 (0.52–0.65)	0.78 (0.72–0.85)	0.80 (0.74–0.86)	0.56 (0.50–0.62)	0.66 (0.61–0.70)
Model 2: visual rating (‘conservative')	No and ‘subtle' lesions	‘Obvious' lesions	0.86 (0.82–0.91)	0.48 (0.41–0.56)	0.71 (0.66–0.76)	0.70 (0.62–0.79)	0.71 (0.67–0.75)
Model 3: quantitative (FLAIR rSI)	FLAIR rSI <1.0721	FLAIR rSI >1.0721	0.47 (0.40–0.53)	0.85 (0.80–0.91)	0.82 (0.79–0.89)	0.52 (0.46–0.58)	0.61 (0.57–0.66)
Model 4: CART	Leafs A–D	Leaf E	0.91 (0.87–0.94)	0.47 (0.39–0.55)	0.72 (0.67–0.77)	0.78 (0.69–0.86)	0.73 (0.69–0.77)
Model 5: CART	Leafs A, B, D	Leafs C, E	0.62 (0.56–0.68)	0.77 (0.71–0.84)	0.80 (0.74–0.86)	0.58 (0.51–0.65)	0.68 (0.63–0.72)
Model 6: CART	Leafs A, C, D	Leafs B, E	0.60 (0.54–0.66)	0.65 (0.58–0.73)	0.72 (0.66–0.78)	0.52 (0.46–0.57)	0.62 (0.57–0.67)
Model 7: CART	Leafs A, D	Leafs B, D, E	0.33 (0.27–0.39)	0.95 (0.92–0.98)	0.90 (0.84–0.97)	0.52 (0.46–0.57)	0.57 (0.54–0.59)
Model 8: CART	Leafs A, C	Leafs B, D, E	0.55 (0.49–0.62)	0.66 (0.59–0.70)	0.71 (0.64–0.77)	0.50 (0.44–0.57)	0.60 (0.55–0.65)
Model 9: CART	Leaf A	Leafs B, C, D, E	0.27 (0.21–0.33)	0.96 (0.93–0.99)	0.91 (0.85–0.98)	0.47 (0.42–0.53)	0.55 (0.52–0.57)

CART, Classification and Regression Tree; CI, confidence interval; FLAIR, fluid-attenuated inversion recovery; NPV, negative predictive value; PPV, positive predictive value; rSI, relative signal intensity.

Classification describes the algorithm applied to results from individual rating methods to binary groups of ‘FLAIR-positive' and ‘FLAIR-negative' patients

Accuracy describes the fraction of correctly classified patients.