Kanno 2003.

Methods	Study design: parallel, 2‐arm RCT Time frame: not reported Duration of follow‐up: 3 years
Participants	Setting: single centre Country: Japan Inclusion criteria: biopsy‐proven IgAN, aged 12 to 65 years Number (analysed/randomised): treatment group (6/8); control group (4/7) Mean age ± SD (years): treatment group (30 ± 5); control group (37 ± 5) Sex (M/F): treatment group (7/1); control group (5/2) Exclusion criteria: not reported
Interventions	Treatment group Prednisolone 0.5 mg/kg/day for approximately 1 month, when a 10% taper was instituted until the dose reached 0.12 mg/kg/day; for 36 months Control group Warfarin: 5 mg given for the first 2 days with further doses adjusted according to the value of the thrombotest, targeting around 30% Co‐interventions Not reported
Outcomes	Urinary protein excretion SCr
Notes	Funding: not reported Trials registration identification number: not applicable
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information to permit judgement
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open‐label study
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding of outcome assessment not specifically reported. Key outcomes were objective laboratory measures and were unlikely to be affected by any knowledge of treatment allocation
Incomplete outcome data (attrition bias) All outcomes	High risk	5/15 patients did not complete study (2 in the treatment group and 3 in the control group)
Selective reporting (reporting bias)	High risk	There was no pre‐specified protocol identified for this study. The study did not report extractable data for the key outcomes that would be expected for a study of this type (e.g., death (any cause), GFR loss, infection)
Other bias	Low risk	The study appears to be free of other sources of bias