Rosman 2 1984.

Study characteristics
Methods	Study design: parallel RCT Study duration: January 1982 to January 1984 Study follow‐up period: 153 of 248 followed up for at least 36 months
Participants	Country: Netherlands Setting: single centre CKD with CrCl 10 to 30 mL/min/1.73 m2 Number: very low protein diet (56); normal protein diet group (41) Mean age (range): 48 years (15 to 73) Sex M/F ratio: 0.54 Exclusion criteria: immunological diseases or cancer; patients on NSAIDs
Interventions	Very low protein diet group (Group C) Prescribed protein intake: 0.4 g protein/kg/day Calculated protein intake: not reported (graphical only) Normal protein diet group (Group A2) Prescribed protein intake: free diet Calculated protein intake: not reported (graphical only) Co‐interventions Antihypertensive medications; sodium restriction; vitamin supplement; phosphate binders
Outcomes	GFR measured by slope of reciprocal SCr (1/SCr) over time Number with ESKD Number of deaths Weight
Notes	Updated report (1989) from previous paper (Lancet 1984; ii:1291‐1296) Eight participants received a renal transplant in the low protein diet group and four in the control group and were counted as renal death event Data from total of 248 participants included in review Funding source: 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	Insufficient information to permit judgement
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not blinded and lack of blinding may influence patient management
Blinding of outcome assessment (detection bias): End or change in GFR End of change in GFR	Low risk	End point of CrCl is a laboratory outcome and unlikely to be influenced by lack of blinding
Blinding of outcome assessment (detection bias): Need to start dialysis Need to start dialysis	Low risk	Need to start dialysis determined by CrCl < 4 mL/min/1.73 m2 Also included in analysis of ESKD were participants who received pre‐emptive transplants
Incomplete outcome data (attrition bias) All outcomes	Low risk	4% (10/248) excluded from analysis (lost to follow up 9, withdrawn 1)
Selective reporting (reporting bias)	Low risk	Reported ESKD, GFR, death and weight but weight and GFR data not able to be included in meta‐analyses
Other bias	Unclear risk	Insufficient information to permit judgement