Table 2.

The areas under the receiver-operating characteristic curves (AUC) and cut-off values for detecting inadequate anesthesia in the Nasal Photoplethysmography Index (NPI), Surgical Plethysmographic Index (SPI), and Analgesia Nociception Index (ANI) in surgical patients.

	NPI	SPI	ANI
AUC (95% CI)	0.733 (0.655–0.802)	0.722 (0.643–0.791)	0.668 (0.586–0.742)
P value	<0.0001	<0.0001	0.0003
Cut-off value (sensitivity %, specificity %)	21.8 (59.3, 82.6)	35.5 (86.8, 45.7)	67 (71.2, 60.4)

NPI values were calculated using the intraoperative NPI equation.