Turner 1994.

Methods	Study design: parallel RCT Study duration: not reported Study follow‐up: 3 POD
Participants	Country: Australia Setting: single centre Inclusion criteria: patients undergoing elective open cholecystectomy Number: treatment group (24); control group (24) Mean age ± SD (years): treatment group (56.5 ± 16.6); control group (49.0 ± 15.3) Sex (M/F): treatment group (8/16); control group (10/14) Exclusion criteria: history of peptic ulceration; bleeding disorder; kidney impairment; haemorrhoids
Interventions	Treatment group Indomethacin suppositories: 200 mg at end of surgery then 100 mg twice daily for 3 days Control group Placebo suppositories: according to same treatment regimen.
Outcomes	Pre‐operative and post‐operative (48 h) SCr was measured in 19/50 patients
Notes	No pre‐operative and post‐operative SCr measures given, rather the mean change was given for each group Funding Source: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Study was described as randomised, method of randomisation was not reported
Allocation concealment (selection bias)	Low risk	Sequential selection of previously randomised envelopes, study drugs appearing identical
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Patients, nursing staff and medical staff were blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Patients, nursing staff and medical staff were blinded
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	50 patients were included in the study, 2 patients were withdrawn due to protocol violation. Of the remaining 48 patients kidney outcome data was available from 38 patients (11% missing data). No reasons for missing data was provided
Selective reporting (reporting bias)	Low risk	Study protocol matches outcomes presented
Other bias	Unclear risk	Insufficient information to permit judgement