Table 3.

Model performance for different cutoff points of the predicted probabilities for TREC with regards to CD4.

Cutoff (probability) (probability)	PPV (%)	NPV (%)	Sensitivity (%)	Specificity (%)	Youden index
0.5	72	76	94	34	27.9
0.55	76	59	77	58	35.1
0.6	79	51	61	71	32
0.65	81	47	48	80	27.9
0.7	83	44	36	87	23.6
0.75	87	42	28	93	20.7

Optimum cut-off point based on maximum value of the J index is presented in bold.