Table 4. Diagnostic yield of magnifying NBI applying UMEC for gastric lesions.

	Sensitivity % (95 % CI)	Specificity % (95 % CI)	PPV % (95 % CI)	NPV % (95 % CI)	Accuracy % (95 % CI)	Kappa value (95 % CI) P value
S-UMEC 1/2A vs 2B/3 (non-cancer vs cancer)
Endoscopist A	84.6 (76.8–86.7)	98.0 (92.1–99.6)	97.1 (88.1–99.5)	89.3 (83.8–90.7)	92.2 (85.4–94.0)	0.73 (0.59–0.87) P  < 0.001
Endoscopist B	97.1 (87.5–99.5)	80.4 (74.5–81.8)	75.0 (67.6–76.9)	97.8 (90.8–99.6)	86.7 (79.4–88.5)

NBI, narrow-band imaging; UMEC, unified magnifying endoscopic classification; PPV, positive predictive value; NPV, negative predictive value; CI, confidence interval.