Table 3

Sensitivity, specificity, positive and negative predictive values of 30-day mortality of the two different prediction rules CRB-65 and DS CRB-65*

	30-day mortality	Cut-off	Sensitivity	Specificity	PPV	NPV
CRB-65
0	1/376 (0)	≥0	100	0	7	NA
1	18/471 (4)	≥1†	99	34	10	100
2	35/247 (14)	≥2	76	76	19	98
3	24/74 (32)	≥3	32	95	33	95
4	2/4 (50)	4	2	100	50	93
DS CRB-65
0	0/295 (0)	≥0	100	0	7	NA
1	2/301 (1)	≥1	100	27	9	100
2	12/239 (5)	≥2	98	54	14	100
3	19/195 (10)	≥3	82	75	20	98
4	30/106 (28)	≥4	59	91	33	97
5	16/34 (47)	≥5	21	98	47	94
6	1/2 (50)	6	1	100	50	93

*Data presented as number total (%).
†Cut-off point accepted as threshold to define high-risk groups according to original study design.9
CRB-65, PPV, positive predictive value; NPV, negative predictive value.