Table 1. Study and patient characteristics.

No.	Study characteristics				Sample characteristics			Indications for CE
	Reference, year, country	Study type	Study aim	ROB (STROBE score)/Ouality	Patients, n	Age, (Mean)	Male, n (%)	Main referral indication
1	Gay et al., 2006, France	Prospective, single center	Utility of CE in predicting DBE route of insertion	26/Very high	164	54	90 (54.88 %)	OGIB
2	Lin et al., 2008, Taiwan	Retrospective, single center	Evaluate combined use of CE and DBE in patients with OGIB	14/Low	10	63	3 (30 %)	OGIB
3	Li et al., 2009, China	Prospective, single center	Utility of CE in predicting DBE route of insertion	21//High	60	49	31 (51.66 %)	GIB
4	Nakamura et al., 2010, Japan	Retrospective, single center	Clarification on the accuracy of the transit time of CE to the lesion as a predictive indicator for DBE insertion route	27/Very high	65	62	37 (56.92 %)	OGIB
5	Chalazan et al., 2012, USA	Retrospective, single center	Determination if SBTT can be used to select the enteroscopy technique	28/Very high	22	71	10 (33.33 %)	OGIB
6	Maeda et al., 2015, Japan	Retrospective, single center	Demonstrate the strategy of initial CE in OGIB, followed by DBE	24/High	89	70	48 (53.93 %)	GIB
7	Tsuboi et al., 2019, Japan	Retrospective, single center	Usefulness of RAPID indicator in choosing the DBE insertion route	29/Very high	50	69	33 (66 %)	OGIB

CE, capsule endoscopy; DBE, double balloon enteroscopy; GIB, gastrointestinal bleeding; OGIB, obscure gastrointestinal bleeding; ROB, risk of bias; SBTT, small bowel transit time.