Julian 1993.

Methods	Study design: parallel, 2‐arm RCT Time frame: started March 1990 Duration of follow‐up: 2 years
Participants	Setting: multicentre (6 sites) Country: USA Inclusion criteria: IgAN; CrCl > 25 mL /min/1.73 m2 Number (analysed/randomised): not reported/35 Mean age ± SD (years): women (34 ± 3); men (39 ± 3) Sex (M/F): 26/9 Exclusion criteria: IgA disease secondary to other causes (HSP, SLE, celiac disease, liver disease); DM; cataracts; osteonecrosis; active peptic ulcer disease; pregnancy
Interventions	Treatment group Alternate‐day prednisone: 60 mg for 3 months, 40 mg for 3 months, 30 mg for 6 months, 25 mg for 3 months, 20 mg for 3 months, 15 mg for 3 months, 10 mg for 3 months Control group No treatment Co‐interventions Not reported
Outcomes	Change in kidney function (reciprocal of SCr) SCr Urinary protein excretion Adverse events Kidney failure
Notes	Preliminary findings only reported Funding: "This work was supported in part by the National Institute of Health, grant number AI‐1875 and DK 40177." Trials registration identification number: not applicable
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random numbers
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	High 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. Reporting of adverse events may have been influenced by knowledge of treatment allocation
Incomplete outcome data (attrition bias) All outcomes	High risk	This is a preliminary report ‐ only 3 patients had completed the full 2 year study; 24 remain in the study and 21 of these have completed at least 6 months and 16 have completed 12 months
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	Unclear risk	Insufficient information to permit judgement. Methods of randomisation, baseline characteristics were not reported to assess quality of randomisation