Wang 2014.

Methods	A prospective randomized controlled trial (registration no. ChiCTR‐TRC‐14004830) Allocation sequence: adequate, reported computer‐generated random numbers Allocation concealment: adequate. We considered both allocation sequence generation and allocation concealment to be adequate. Blinding: no mention Follow‐up: adequate, withdrawn: n = 0 Dropouts: n = 0 Intention‐to‐treat analysis: no mention Sample size calculation: no mention Informed consent: reported Ethics committee: approval
Participants	Country: China Single center: Department of Hepatobiliary and Pancreatic Surgery, the First Affiliated Hospital, Harbin Medical University, 219 participants were accrued from 1 January 2010 to 1 March 2013 No. randomized: 219 Age: 24 to 77 years Gender: Male/Female: 113/106 Inclusion criteria: Underwent PD Definition of pancreatic fistula: ISGPF (2005) definition Conflicts of interest: none
Interventions	All participants underwent PD. 219 participants were randomly assigned to 1 of 2 groups: Group 1: External drainage (n = 110) Group 2: Internal drainage (n = 109)
Outcomes	The main outcome measures were: Mortality, morbidity of pancreatic fistula Delayed gastric emptying Abdominal infection Intestinal obstruction Overall complications Intraoperative blood loss Operative duration Postoperative hospital stay
Notes	All participants underwent PD, no participants were withdrawn, and no participants dropped out
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Reported computer‐generated random numbers
Allocation concealment (selection bias)	Low risk	Sealed envelopes
Blinding (performance bias and detection bias) All outcomes	Unclear risk	No mention
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not clearly reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not explained
Incomplete outcome data (attrition bias) All outcomes	Low risk	Detailed information
Selective reporting (reporting bias)	Low risk	Reported detailed outcomes
Other bias	Unclear risk	No mention