Updated meta-analysis of pancreatic stent placement in preventing post-endoscopic retrograde cholangiopancreatography pancreatitis

Table 2 Quality of included studies

Ref.	Concealment of randomization	Double-blinding	Risk of losing data
Smithline et al[16], 1993	-	-	-
Sherman et al[17], 1996	-	-	NK
Tarnasky et al[12], 1998	+	-	NK
Patel et al[18], 1999	-	-	NK
Fazel et al[19], 2003	+	-	+
Harewood et al[20], 2005	+	-	+
Sofuni et al[21], 2007	+	-	+
Tsuchiya et al[22], 2007	+	-	-
Ito et al[23], 2010	+	-	-
Pan et al[24], 2011	-	-	-
Sofuni et al[25], 2011	+	-	-
Kawaguchi et al[26], 2012	+	-	-
Cha et al[27], 2012	-	-	-
Lee et al[28], 2012	+	-	-

+: Reported or used with relatively lower risk; -: Not reported or not used with potential risk; UK: Unknown.