Koike 2008.

Methods	Study design: parallel, 2‐arm RCT Time frame: not reported Duration of follow‐up: 24 months
Participants	Setting: single centre Country: Japan Inclusion criteria: IgAN on renal biopsy (mild inflammatory activities, presence of cellular and/or fibrocellular crescents, mesangial interposition with mononuclear cell infiltration and interstitial inflammatory cell infiltration) Number analysed/randomised: treatment group (24/24); control group (24/24) Mean age ± SD (years): treatment group (37.9 ± 10.1); control group (38.3 ± 12.7) Sex (M/F): treatment group (6/18); control group (5/19) Exclusion criteria: systemic diseases, such as DM, collagen disease, abnormal hyper gamma globulinaemia and chronic liver disease
Interventions	Treatment group Prednisolone: 0.4 mg/kg/d for 4 weeks, and the dose was gradually reduced to 10 to 20 mg on alternate days for the next 12 months, and then 5 to 10 mg on alternate days for a subsequent year. When the treatment was effective, alternate‐day prednisolone 5 to 10 mg administration was continued during the next follow‐up period. When the treatment was not effective, the dose was further reduced to discontinuation Dipyridamole or dilazep hydrochloride: 150 or 300 mg/d for 24 months Control group Dipyridamole or dilazep hydrochloride: 150 or 300 mg/d for 24 months Co‐interventions ACEi
Outcomes	Urinary protein excretion SCr Haematuria BP
Notes	Funding: not reported Trials registration identification number: not reported
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	Quote: "Two doctors who did not know the histological scores randomly assigned the patients to either the steroid or control group. The doctors used two envelopes consisting of A (steroid group) or B (control group) and containing study instructions"
Blinding of participants and personnel (performance bias) All outcomes	High risk	Unable to blind due to the tapering of the prednisolone
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	Low risk	All participants were included in study follow‐up
Selective reporting (reporting bias)	High risk	Key outcomes expected for this type of study (death (any cause), malignancy, infection) were not reported
Other bias	High risk	Co‐intervention with antihypertensive therapy was imbalanced between groups (administered to intervention group participants only). There was imbalance in kidney function between groups (the control group participants had a higher mean SCr)