Wilson 2001.

Study characteristics
Methods	RCT. Parallel design with 2 arms. Duration: 9 months (6 months treatment and 3 months follow‐up). Location: multicentre in the USA.
Participants	Inclusion criteria: adults with hypoalbuminaemia (serum albumin 3.5 ‐ 3.7 g/dL) receiving haemodialysis. An additional group is included with severe hypoalbuminaemia (serum albumin 2.5 ‐ 3.4 g/dL) who received intervention according to current practice. Exclusion criteria: < 18 years or > 80 years of age, hospitalisation for longer than 1 week in the past 3 months, major surgery or sepsis in the past 3 months, urea reduction ratio less than 65% for 2 of the past 3 months, unintentional weight loss > 10% in the past 6 months, HIV infection, malignancy, use of appetite stimulanting medication, on haemodialysis for less than 3 months. Number randomised: 32 participants (intervention group, n = 16; control group, n = 16). Attrition: 5 participants were not included in the analysis but details of the group allocation are unclear. Gender split: intervention group 39% males, 61% females; control group 14% males, 86% females. Age: mean (SD) intervention group 64 (10) years; control group 58 (8.6) years. Nutritional status: not reported.
Interventions	Intervention: participants received dietary advice and ONS in the form of dietary counselling to increase energy and protein intakes and 1 ‐ 2 cans of supplement (250 calories per serving). Control: participants received dietary advice alone in the form ofdietary counselling to increase energy and protein intake.
Outcomes	Time to nutritional repletion, number of days spent in hospital*.
Publication details	Language: English. Funding: grant from the council on renal nutrition from the National Kidney Foundation. Publication status: peer‐reviewed journal.
Notes	No usable data from this study.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised, but method not stated.
Allocation concealment (selection bias)	Unclear risk	Not stated.
Blinding (performance bias and detection bias) Clinical outcomes	Low risk	Not stated, but it is unlikely that knowing group allocation would influence number of days spent in hospital.
Blinding (performance bias and detection bias) Functional outcomes	Unclear risk	Not measured.
Blinding (performance bias and detection bias) Nutritional outcomes	High risk	Not blinded and lack of blinding may have influenced assessemnt of achieving nutritional repletion.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not blinded and likely that researchers and participants were aware of group allocation as this was a nutritional intervention. It is possible that assessment of some outcomes was influenced by lack of blinding.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Assessment of some outcomes may have been influenced by lack of blinding.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	5 participants were not included in the analysis but details of the group allocation is unclear, therefore risk of bias.
Selective reporting (reporting bias)	High risk	No study protocol identified, thus unable to judge whether all planned outcomes were reported. The methods section of the paper states that height, weight and weight history and serum albumin are collected at baseline, The results section reports % achieving nutritional repletion defined by improvement in serum albumin and length of hospital stay but no data on weight change. No response received from authors.
Other bias	Unclear risk	Baseline variables given, the dietary counselling and supplement group were significantly older than the dietary group, therefore risk of bias.