Jiang 2008.

Methods	Randomised clinical trial with parallel design. Generation of the allocation sequence and allocation concealment: were not clearly described in the original article Follow‐up: adequate Duration of follow‐up: 30 days
Participants	Patients who were diagnosed with gastric cancer Country: China Year of study: July 2005 to June 2006 Number randomised: 100 Mean age (years): Group 1 (57.3 ± 15.4), Group 2 (56.7 ± 12.4) Sex (M/F): Group 1 (29/20), Group 2 (30/21) Inclusion criteria Age < 80 years No anti‐tumour therapy pre‐operatively, such as chemotherapy, radiotherapy and so on The surgical procedure was D2 lymphadenectomy Exclusion criteria Dysfunction in other organs Palliative operation or emergency operation Combined with splenectomy or pancreatectomy
Interventions	Group 1: drain (n = 49), type of drains was unclear Group 2: no drain (n = 51) Antibiotic use: not stated All patients in the two groups received total or subtotal gastrectomy with D2 lymphadenectomy according to the location of primary tumour. The same group of surgeons performed the operation
Outcomes	Mortality (30‐day mortality) Re‐operations Post‐operative complications Operation time Length of post‐operative hospital stay Initiation of soft diet
Notes	10 ml fibrin glue was used in abdominal cavity after the operation Patients with subtotal or total gastrectomy were not analysed separately Drains were removed when the total output < 100 ml/24 hours
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Unclear
Allocation concealment (selection bias)	Unclear risk	Unclear
Blinding (performance bias and detection bias) All outcomes	Unclear risk	The authors did not record whether or not the drain was placed by a second surgeon
Incomplete outcome data (attrition bias) All outcomes	Low risk	Yes
Selective reporting (reporting bias)	Low risk	Yes
Other bias	Low risk	Yes