Table 4. Comparison of the diagnostic measurements for category 4 /5 lesions with M-NBI diagnosis according to the VS classification system between the non-biopsy group and the biopsy group.

	Non-biopsy group (n = 32)	Biopsy group (n = 67)	P value
Accuracy (95 % CI)	88 % (71.0 – 96.5)	66 % (53.1 – 76.8)	0.02
Sensitivity (95 % CI)	95 % (77.2 – 99.9)	89 % (76.4 – 96.4)	0.39
Specificity (95 % CI)	70 % (34.8 – 93.3)	14 % (3.0 – 36.3)	< 0.01
Positive predictive value (95 % CI)	88 % (67.6 – 97.3)	69 % (56.1 – 80.8)	0.09
Negative predictive value (95 % CI)	88 % (47.3 – 99.7)	38 % (8.5 – 75.5)	0.04

M-NBI, magnifying endoscopy with narrow-band imaging; VS, vessel plus surface; CI, confidence interval.