Non-guided self-learning program for high-proficiency optical diagnosis of diminutive and small colorectal lesions: A single-endoscopist pilot study

Table 1 Patient characteristics, n = 152

Characteristic	Value
Age, yr	61.1 ± 6.2
Female sex n (%)	56 (36.8)
Familiar history of CRC n (%)	33 (21.7)
Number of polyps	3.8 ± 3.0
Number of adenomas	2.7 ± 2.6
Number of advanced adenomas	0.6 ± 1.0

CRC: Colorectal cancer.

Table 2 Lesion characteristics n (%)

Characteristic		1-5 mm	6-9 mm
Number of lesions by size		399 (76.4)	123 (23.6)
Paris classification
	0-Ip	3 (0.7)	22 (17.9)
	0-Is	273 (68.4)	88 (71.5)
	0-IIa	117 (29.3)	11 (8.9)
	0-IIc	2 (0.5)	0
	0-IIa + IIc	3 (0.7)	0
	0-IIb	1 (0.2)	2 (1.6)
Pathology
	Adenoma	255 (63.9)	97 (78.9)
	Hyperplastic	106 (26.6)	17 (13.6)
	SSP	8 (2.0)	7 (5.6)
	Other	26 (6.5)	1 (0.8)
	Lost/not enough sample	4 (1.0)	1 (0.8)
Location
	Proximal	248 (62.2)	56 (45.5)
	Distal	151 (37.8)	67 (54.5)
Optical diagnosis1
	NICE 1	288 (72.2)	102 (82.9)
	NICE 2	110 (27.6)	20 (16.3)
High-confidence diagnosis		347 (87.0)	116 (94.3)

¹Only available for 520 lesions (1 lesion excluded because a poor approach to application of narrow band imaging, and 1 subepithelial lesion). NBI: Narrow band imaging; NICE: NBI International Colorectal Endoscopic classification system; SSP: Sessile serrated polyp.

Table 3 Concordance between proposed surveillance interval between optical diagnosis and pathology, n = 93

Guideline	Concordance		Too long		Too short
	n	% (95%CI)	n	% (95%CI)	n	% (95%CI)
EU	89	95.7 (91.9-100)	2	2.1 (0-21.4)	2	2.1 (0-21.4)
ESGE	90	96.8 (93.5-100)	2	2.1 (0-21.4)	1	1.1 (0-20.5)
ASGE	89	95.7 (91.9-100)	3	3.2 (0-22.3)	1	1.1 (0-20.5)

ASGE: American Society of Gastrointestinal Endoscopy; CI: Confidence interval; ESGE: European Society of Gastrointestinal Endoscopy; EU: European Union.

Table 4 Overall diagnostic performance of narrow band imaging and the Narrow Band Imagig International Colorectal Endoscopic classification system

Parameter	High-confidence		Low-confidence
	1-5 mm, n = 347	6-9 mm, n = 115	1-5 mm, n = 51	6-9 mm1, n = 7
Sensitivity	97.0 (95.2-98.8)	100.0	76.0 (64.3-87.7)	N/A
Specificity	74.3 (69.4-78.6)	94.4 (90.2-98.6)	46.1 (32.4-59.8)	57.1 (20.4-57.1)
PPV	88.5 (84.6-91.4)	99.0 (97.2-100.0)	57.6 (44.0-71.2)	0
NPV	92.3(89.1-94.8)	100.0	66.7 (53.8-79.6)	100.0
LR+	3.8 (1.2-4.8)	18.0 (10.1-23.9)	1.4 (-1.8-4.6)	N/A
Accuracy	89.5 (85.7-92.3)	99.1 (97.4-100.0)	60.7 (47.3-74.1)	57.1 (20.4-57.1)

Data are given as % (95%CI).

¹No adenoma was diagnosed with low-confidence.

CI: Confidence interval; LR: Likelihood ratio; N/A: Non-applicable; NPV: Negative predictive value; PPV: Positive predictive value.

Table 5 Comparison of the diagnostic performance measures and Preservation and Incorporation of Valuable Endoscopic Innovations criteria fulfillment between the two halves of the study

Parameter		1st half, n = 1651	2nd half, n = 1821
Sensitivity		96.1 (93.1-99.0)	97.6 (95.4-99.8)
Specificity		82.0 (76.1-87.9)	65.4 (58.5-72.3)
PPV		90.1 (85.5-94.7)	87.2 (82.3-92.0)
NPV		92.6 (88.6-96.6)	91.9 (87.9-95.9)
Accuracy		90.1 (85.6-94.7)	88.2 (87.9-95.9)
NPV rectosigmoid lesions		92.3 (87.3-96.6)	90.5 (86.2-94.8)
Surveillance interval agreement
	UE	100.0	93.3 (89.7-96.9)
	ESGE	100.0	95.1 (92.0-98.2)
	ASGE	100.0	93.3 (91.6-98.2)

Data are given as % (95%CI).

¹Only for diminutive lesions diagnosed with high-confidence.

ASGE: American Society of Gastrointestinal Endoscopy; ESGE: European Society of Gastrointestinal Endoscopy; EU: European Union; NPV: Negative predictive value; PIVI: Preservation and Incorporation of Valuable Endoscopic Innovations; PPV: Positive predictive value.