Pollak 1993.

Methods	Study design: parallel RCT Time frame: NS
Participants	Inclusion criteria Setting: multicentre (3 centres) Country: USA Kidney transplant recipients Number: treatment group (58); control group (58) Mean age ± SD: treatment group (41.5 ± 1.6); control group (41.5 ± 1.9) Sex (M/F): treatment group (35/23); control group (43/15) Exclusion criteria Planned transplantation with a cadaver kidney preserved in excess of 72 hours
Interventions	Treatment group Human recombinant superoxide dismutase (rh‐SOD) parenteral vial containing 500 mg Control group Placebo (parenteral vial containing 500 mg of lyophilised powder)
Outcomes	GRF at day 6 CrCl at day 6 SCr at 48 hours
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Authors report use of computer‐generated assignment schedule
Allocation concealment (selection bias)	Low risk	Study reported that the only randomisation master code was held by the Bristol‐Myers Company. No investigator had access to randomisation codes until study termination
Blinding (performance bias and detection bias) All outcomes	Low risk	Study reported double blinding. "No investigator had access to the code until the study was terminated."
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information regarding completeness of follow‐up reported, no information regarding the conduct of analyses based on the intention‐to‐treat principle
Selective reporting (reporting bias)	High risk	Study reported in the methods that routine "serum chemistry, cyclosporine blood levels, and hematology" were collected, however, these were not reported in the results
Other bias	High risk	Study reported early termination by the monitor citing that it was "unlikely that a benefit would be shown for rh‐SOD by the addition of 84 extra subjects" Bristol‐Myers Squibb Company supported the study and provided the recombinant SOD. Bristol‐Myers Company held the only master code.