Table 2.

Diagnosis accuracy according to the number of scores.

	1 score		2 scores		3 scores		4 scores		5 scores		6 scores		7 scores		8 scores		19 scores
AUC (95% CI)	.632 (.597–.666)		.684 (.652–.717)		.709 (.677–.742)		.726 (.694–.757)		.741 (.711–.772)		.756 (.726–.786)		.759 (.729–.789)		.771* (.741–.799)		.772 (.743–.8)
Impaired scores ≥	TPR	FPR	TPR	FPR	TPR	FPR	TPR	FPR	TPR	FPR	TPR	FPR	TPR	FPR	TPR	FPR	TPR	FPR
0	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100
1	29.9	3.6	42.7	6.8	50.3	10.5	54.4	12.3	59.9	16.3	63.8	18.9	64.6	19.6	68.1	21.5	75	35
2	.0	.0	14.8	.3	21.9	.6	30.4	1.7	34.1	2.1	40.6	2.8	42.3	3.2	45.8	4.7	59	14
3			.0	.0	6.1	.0	14.1	.3	18.2	.3	24.3	.7	26.5	.7	27.8	1.2	46	6.1
4					.0	.0	4.1	.0	7.6	.0	12.6	.1	14.1	.3	15.4	.3	38.2	2.35
Sensitivity	29.9		14.8		21.9		30.4		34.1		40.6		42.3		45.8		38.2
Specificity	96.4		99.7		99.4		98.3		97.9		97.2		96.8		95.3		97
Accuracy	73.9		66.6		66.6		68.3		66.9		67.3		67.5		67.4		74.6
Positive PV	81.0		96.5		95.3		90.4		89.4		88.3		87.2		83.3		86.7
Negative PV	72.9		69.5		71.3		73.4		74.3		76.1		76.6		77.4		75.4

AUC: Area Under Curve; CI: confidence interval; TPR: True positive rate; FPR: false-positive rate; PV: predictive value. Underlined bold rates: False-positive rate ≤5% and corresponding true positive rate;

^athe AUC for the 8-score set was higher than those obtained with 7 scores or less (p≤.01 for all comparisons in an extended McNemar test).