Table 4.

Performance metrics of 4C Mortality Score to rule out and rule in mortality at different cut-off values in validation cohort

Cut-off value	No of patients (%)			TP		TN	FP	FN	Sensitivity (%)		Specificity (%)		PPV (%)		NPV (%)		Mortality (%)
Rule out mortality
≤2	1001 (4.5)			6724		996	14 636	5	99.9		6.4		31.5		99.5		0.5
≤3	1650 (7.4)			6709		1630	14 002	20	99.7		10.4		32.4		98.8		1.2
≤4	2420 (10.8)			6672		2363	13 269	57	99.2		15.1		33.5		97.6		2.4
≤6	4121 (18.4)			6542		3934	11 698	187	97.2		25.2		35.9		95.5		4.5
≤8	6539 (29.2)			6223		6033	9599	506	92.5		38.6		39.3		92.3		7.7
≤9	8167 (36.5)			5911		7349	8283	818	87.8		47		41.6		90.0		10.0
Rule in mortality
≥9		15 822 (70.8)	6223		6033		9599	506	92.5	38.6		39.3		92.3		39.3
≥11		12 325 (55.1)	5483		8790		6842	1246	81.5	56.2		44.5		87.6		44.5
≥13		8069 (36.1)	4206		11 769		3863	2523	62.5	75.3		52.1		82.3		52.1
≥15		4158 (18.6)	2557		14 031		1601	4172	38	89.8		61.5		77.1		61.5
≥17		1579 (7.1)	1142		15 195		437	5587	17	97.2		72.3		73.1		72.3
≥19		381 (1.7)	305		15 556		76	6424	4.5	99.5		80.1		70.8		80.1

FN=false negative; FP=false positive; NPV=negative predictive value; PPV=positive predictive value; TN=true negative; TP=true positive.