Land 1994.

Methods	Study design: parallel RCT Time frame: January 1987 to October 1988
Participants	Inclusion criteria Setting: single centre Country: Germany Patients who had received a cadaveric kidney transplant Number: treatment group (81); control group (96) Mean age ± SD: treatment group (45.5 ± 12.0); control group (45.6 ± 13.0) Sex (M/F): treatment group (53/28); control group (77/19) Exclusion criteria: NS
Interventions	Treatment group Recombinant human superoxide dismutase (rh‐SOD) 200 mg in 50 mL saline Control group 200 mg sucrose in 50 mL saline as placebo
Outcomes	All‐cause mortality Patient and graft survival rates within the first year and long term results included 4 year graft and patient survival rates Chronic progressive transplant dysfunction requiring dialysis
Notes	Retrospective analysis of data collected in prospective RCT (double‐blinded and placebo controlled)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Study reports randomisation of patients, however, procedure was not described
Allocation concealment (selection bias)	Unclear risk	One of the authors (HS) of the study (although not involved in the patients' care) received the "randomisation code". This author was responsible for collecting all information about study. Study reports that the physicians in charge and the patients were not informed about the initial treatment. No information was provided regarding randomisation methodology
Blinding (performance bias and detection bias) All outcomes	Low risk	Study reported the use of double blinding
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Reported complete follow‐up, no information regarding the conduct of analyses based on the intention‐to‐treat principle
Selective reporting (reporting bias)	Low risk	The study protocol is not separately available but the published report includes all expected outcomes
Other bias	High risk	Funding: Two authors employees of 1) Shaman Pharmaceuticals (San Carlos, CA) and 2) The Lipsome Company Inc (Princeton, NJ)