Poor agreement between endoscopists and gastrointestinal pathologists for the interpretation of probe-based confocal laser endomicroscopy findings

Table 1 Summary of patient and lesions characteristics n (%)

Characteristics
Age (yr)	Mean ± SD		60.3 ± 13.6
	Median		61.5
	IQR		51-71
	Range		17-86
Gender	Female		22 (33.3)
	Male		44 (66.7)
Race	Black		7 (10.6)
	White		54 (81.8)
	Other		5 (7.6)
Lesion type	Esophagus	All	40 (60.6)
		Normal/Benign	12 (30)
		LGD	13 (32.5)
		HGD	8 (20)
		Neoplastic	7 (17.5)
	Gastric	All	7 (10.6)
		Normal/Benign	2 (28.6)
		LGD	1 (14.3)
		HGD	2 (28.6)
		Neoplastic	2 (28.6)
	Colonic	All	1 (1.5)
		Normal/Benign	0
		LGD	0
		HGD	1 (100)
		Neoplastic	0
	Ampulla	All	3 (4.5)
		Normal/Benign	2 (66.7)
		LGD	0
		HGD	1 (33.3)
		Neoplastic	0
	Pancreaticobiliary	All	15 (22.7)
		Normal/Benign	4 (26.7)
		LGD	0
		HGD	1 (6.7)
		Neoplastic	10 (66.7)
Indication for pCLE	Indeterminate lesion		34 (51.5)
	Surveillance		18 (27.3)
	Targeted biopsy ± therapy		13 (19.7)
	Other		1 (1.5)

pCLE: Probe-based confocal laser endomicroscopy.

Table 2 Comparison of diagnostic accuracy between endoscopists and pathologist

	Lesion site	Sensitivity (95%CI)	Specificity (95%CI)	PPV(95%CI)	NPV(95%CI)	Accuracy (95%CI)
Endoscopist	All lesion types	87.0	80.0	90.9	72.7	84.8
		(77.2-96.7)	(62.4-97.5)	(82.4-99.4)	(54.1-91.3)	(76.2-93.5)
	Luminal1	82.4	92.9	96.6	68.4	85.4
		(69.5-95.2)	(66.1-99.8)	(82.2-99.9)	(47.5-89.3)	(75.4-95.4)
	Ampulla/PB	100	50.0	80.0	100	83.3
		(73.5-100)	(11.8-88.2)	(51.9-95.7)	(29.2-100)	(58.6-96.4)
Pathologist	All lesion types	69.6	40.0	72.7	36.4	60.6
		(56.3-82.9)	(18.5-61.5)	(59.6-85.9)	(16.3-56.5)	(48.8-72.4)
	Luminal1	64.7	42.9	73.3	33.3	58.3
		(48.6-80.8)	(16.9-68.8)	(57.5-89.2)	(11.6-55.1)	(44.4-72.2)
	Ampulla/PB	83.3	33.3	71.4	50.0	66.7
		(51.6-97.9)	(4.3-77.7)	(41.9-91.6)	(6.8-93.2)	(41.0-86.7)
P value for overall rates:		-	-	-	-	< 0.0012
P value for luminal lesions:		-	-	-	-	< 0.0012
P value for PB lesions:		-	-	-	-	0. 3752

¹Luminal lesions include lesions located in the esophagus, stomach and colon.

²P values were calculated using the McNemar’s test to compare the diagnostic accuracy between endoscopist and pathologist. P values cannot be calculated for sensitivity, specificity, NPV or PPV. PPV: Positive predictive value; NPV: Negative predictive value; PB: Pancreaticobiliary.

Table 3 Inter-observer variation between endoscopists and pathologist

		Agreement	kappa	P value
Overall (all lesion types)		73.7%	0.43	< 0.001
Lesion site:	Luminal	75.0%	0.40	< 0.001
	Ampulla/PB	70.4%	0.19	0.191
Degree of abnormality	Benign	60.0%	0.13	0.102
	Dysplasia	84.0%	0.58	< 0.001
	Neoplasia	73.7%	0.07	0.114
	Dysplasia/neoplasia combined	79.7%	0.55	< 0.001