Comparison between endoscopic sphincterotomy vs endoscopic sphincterotomy associated with balloon dilation for removal of bile duct stones: A systematic review and meta-analysis based on randomized controlled trials

Table 1 Descriptive table of bias in therapeutic studies

Study	Heo, 2007	Kim TH, 2009	Kim HG, 2009	Hong, 2009	Teoh, 2013	Li, 2013	Qian, 2013	Guo, 2015	Takeshi, 2015	Karsenti, 2017	Chu, 2016
Question	ESBD vs ES	ESBD vs ES	ESBD vs ES	ESBD vs ES	ESBD vs ES	ESBD vs ES	ESBD vs ES	ESBD vs ES	ESBD vs ES	ESBD vs ES	ESBD vs ES
Randomization	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes
Allocation	Yes	Do not quote	Do not quote	Do not quote	Yes	Yes	Yes	Do not quote	Do not quote	Yes	Yes
Blindness	No	No	No	No	No	No	No	No	No	No	No
Losses	No	No	No	Do not quote	No	Yes	Yes	No	No	No	Yes
Prognosis	Homogeneous	Homogeneous	Homogeneous	Homogeneous	Homogeneous	Homogeneous	Homogeneous	Statistical difference in the population with the highest rate of periampular diverticulum in the ESBD group	Homogeneous	Age significantly higher in ES population compared with ESBD population	Homogeneous
Outcomes	Extraction rate of stones, bleeding, pancreatitis, perforation, use of ML and cholangitis	Extraction rate of stones, bleeding, pancreatitis, perforation, use of ML	Extraction rate of stones, bleeding, pancreatitis, perforation, use of ML and cholangitis	Extraction rate of stones, bleeding, pancreatitis, perforation and cholangitis	Extraction rate of stones, perforation, use of ML and cholangitis	Extraction rate of stones, perforation, use of ML and cholangitis	Extraction rate of stones, perforation, use of ML, cholangitis. And recurrence of choledocolithiasis	Extraction rate of stones, bleeding, pancreatitis, perforation, use of ML and cholangitis	Extraction rate of stones, bleeding, perforation, use of ML and cholangitis	Extraction rate of stones, bleeding, pancreatitis, perforation	Extraction rate of stones, bleeding, pancreatitis, perforation, use of ML and cholangitis
ITT	Yes	Yes	Yes	Yes	Yes	Modified ITT analysis	Yes	Yes	Yes	Yes	No

ML: Mechanical lithotripsy; ITT: Intention-to-treat analysis.