1. Events of the composite outcome 'overall morbidity'.

Author	Lella 2006	Morino 2006	Rabago 2006	Tzovaras 2012	Sahoo 2014
Hemobilia	NR	X	NR	X	NR
Acute respiratory failure with admission to intensive care unit	NR	X	NR	no	NR
Early incisional hernia	NR	X	NR	no	NR
Bile leak	NR	no	NR	X	NR
Cholangitis	NR	no	NR	X	NR
Bleeding from sphincterotomy	NR	no	NR	X	NR
Bleeding form drain site	NR	no	NR	X	NR
Collection/biloma	NR	no	NR	X	NR
Wound infection	NR	no	NR	X	NR
Urinary retention (UTI)	NR	no	NR	X	NR
Duodenal perforation	X	no	NR	no	X

NR: the authors did not report the type of post‐operative complications
 X: the authors reported the type of post‐operative complications
 no: the authors did not report the type of post‐operative complications