Garneata 2013.

Methods	Study design: parallel RCT Study duration: March 2006 to April 2009 Study follow‐up period: 15 months
Participants	Country: Romania Setting: Single centre; renal outpatient clinic Stable GFR for 3 months before enrolment while receiving low protein diet (0.6 g/kg/d); CKD stage 4 (GFR < 30 mL/min/1.73 m2); agreed to keep to the diet and to the monitoring schedule; compliance confirmed if protein & energy intake ± 10% & visit adherence ± 7 days after 1st visit Number: very low protein diet group (104); low protein diet group (103) Median age (years): very low protein diet group (55.2); low protein diet group (53.6) Sex M/F: very low protein diet group (65/39); low protein diet group (61/42) Exclusion criteria: poorly controlled hypertension; diabetes; heart failure; malabsorption; liver disease; chronic inflammation; uraemic symptoms; anorexia
Interventions	Very low protein diet group Prescribed protein intake: 0.3 g vegetable protein/kg/d + Ketosterol 1 tablet/5 kg body weight Calculated protein intake: median 0.29 g/kg/d (0.29 to 0.31) during 1 year Low protein diet group Prescribed protein intake 0.6 g protein/kg/d Calculated protein intake: median 0.58 g/kg/d (0.57 to 0.59) during 1 year Both groups received 30 kcal/d Co‐interventions Water soluble vitamins, nutritional counselling, antihypertensive and lipid lowering agents, iron supplements and EPO, vitamin D and calcium supplements, phosphate binders
Outcomes	Need to start dialysis Death (all causes) SGA, BMI
Notes	Information on sequence generation and allocation concealment requested from authors and received Funding source: none received
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomised using computer generated numbers
Allocation concealment (selection bias)	Low risk	Allocation utilising opaque envelopes
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 eGFR (calculated from serum creatinine by MDRD formula) is a laboratory measure 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	End point of the onset of ESKD determined by committee without knowledge of treatment groups
Incomplete outcome data (attrition bias) All outcomes	Low risk	3.3% lost to follow up/discontinued diet but all participants included in analyses
Selective reporting (reporting bias)	Low risk	Expected outcomes (ESKD, death (all causes), GFR, BMI) reported
Other bias	Low risk	No funding support received