Assistant skill in gastric endoscopic submucosal dissection using a clutch cutter

Table 3 Factors associated with the difficulty of endoscopic submucosal dissection

	No. of patients	No. of events	Univariate			Multivariatea
			OR	95%CI	P value	OR	95%CI	P value
Location					0.52			0.49
Middle third	20	9	1.64	0.37-7.25		2.09	0.17-12.3
Lower third	12	4	1	Reference		1	Reference
Position					0.60			0.73
Non-GC	13	6	1.47	0.35-6.17		0.68	0.08-5.73
GC	19	7	1	Reference		1	Reference
Assistant skill					0.016a			0.021a
Non-expert	16	10	7.22	1.44-36.20		16.5	1.52-178.00
Expert	16	3	1	Reference		1	Reference
Resected area					0.025a			0.023a
≥ 500 mm2	12	8	6.00	1.25-28.8		15.3	1.46-159.00
< 500 mm2	20	5	1	Ref.		1

^aSignificant value. Adjusted for all factors in this table. ESD: Endoscopic submucosal dissection; ESD-C: ESD using a clutch cutter; GC: Greater curvature; No: Number; OR: Odds ratio.