TABLE 6.

The sensitivity, specificity, positive predictive, and negative predictive values (NPVs) of the HbO₂ cut-off point for differentiating healthy controls from schizophrenia patients at the right orbitofrontal cortex during the verbal fluency test (VFT).

HbO2 cut-off point (Unit: μ M)	Sensitivity	Specificity	Positive predictive value	Negative predictive value	Correctly classified	Youden’s index
0.088	0.85	0.64	0.85	0.65	0.70	0.49
0.102	0.85	0.65	0.85	0.65	0.71	0.50
0.112	0.85	0.65	0.85	0.66	0.71	0.51
0.121	0.85	0.66	0.85	0.66	0.72	0.51
0.130	0.85	0.67	0.86	0.67	0.73	0.52
0.136	0.85	0.68	0.86	0.67	0.73	0.53
0.155	0.85	0.69	0.86	0.67	0.74	0.54
0.169	0.85	0.70	0.87	0.67	0.75	0.55
0.208	0.85	0.71	0.87	0.67	0.75	0.56
0.209*	0.85	0.72	0.88	0.68	0.76	0.57
0.212	0.83	0.72	0.88	0.64	0.75	0.55
0.213	0.81	0.72	0.87	0.62	0.75	0.53
0.250	0.79	0.72	0.87	0.60	0.74	0.51
0.265	0.77	0.72	0.87	0.57	0.73	0.48
0.280	0.74	0.72	0.86	0.55	0.73	0.46
0.291	0.74	0.73	0.86	0.55	0.73	0.47
0.300	0.72	0.73	0.86	0.53	0.73	0.45
0.313	0.72	0.74	0.87	0.54	0.73	0.46
0.317	0.70	0.74	0.87	0.51	0.73	0.44

*Optimal cut-off value of oxy-hemoglobin, >Optimal cut-off suggests healthy control; <Optimal cut-off suggests the diagnosis of schizophrenia.