Table 4.

Point estimates for pleural fluid/serum ratio of CEA.

Cut-off value	Specificity	Sensitivity	PPV	NPV	LHR+	LHR–	J
0.5	0.45	0.93	0.61	0.87	1.69	0.16	0.38
0.8	0.70	0.87	0.73	0.85	2.90	0.19	0.57
1.0	0.92	0.85	0.91	0.87	10.63	0.16	0.77
1.2	0.94	0.78	0.92	0.82	13.00	0.23	0.72
1.5	0.95	0.66	0.92	0.75	13.20	0.36	0.61

CEA, carcinoembryonic antigen; J, Youden’s index; LHR+, positive likelihood ratio; LHR−, negative likelihood ratio; NPV, negative predictive value; PPV, positive predictive value.