Clutch Cutter knife efficacy in endoscopic submucosal dissection for early gastric neoplasms

Table 2 Matching factors between two groups after propensity score matching

	ESD-C n = 44	ESD-O n = 44	P value	ASD
Variable matching between groups
Age, yr; mean ± SD	73.16 ± 8.59	71.11 ± 8.81	0.2732	0.2360
Sex: Male/female	8/36	6/38	0.7721	0.1250
Underlying disease: No/yes	28/16	29/15	11	0.0476
Anti-thrombotic drugs: No/yes	2/42	3/41	11	0.0983
Tumor location: Upper third/others	7/37	2/42	0.2501	0.3810
Tumor position: Lessor/others	19/25	21/23	0.8311	0.0914
Morphology: Flat or depressed/others	25/19	28/16	0.6631	0.1400
Histology: Undifferentiated/others	0/44	0/44	-	0
Tumor size, mm: mean ± SD	16.89 ± 12.65	20.90 ± 13.30	0.0762	0.3090
Tumor depth: Mucosa/submucosa	Jun-38	Jun-38	11	0
Ulceration, positive	6 (13.6%)	4 (9.1%)	0.7391	0.1440
Operator skill: Expert/trainee	14/30	14/30	11	0

¹P value was calculated using Fisher’s exact test;

²P value was calculated using a t test for continuous data. ESD-C: Endoscopic submucosal dissection with Clutch Cutter; ESD-O: Endoscopic submucosal dissection with another end-knife; SD: Standard deviation; ASD: Absolute standardized difference.