Hamedi‐Kalajahi 2021.

Study characteristics
Methods	Study characteristics Study design: parallel RCT Study duration: August 2019 to October 2019 Study follow‐up: 10 weeks
Participants	Baseline characteristics Country: Iran Setting: Children’s Hospital and University Hospital (2 sites) Inclusion criteria: CKD patients aged 6 to 18 years; at least 2 dialysis sessions/week; HD for at least 3 months Randomised number (intervention/control): 15/15 Dialysis modality: HD Mean age ± SD (years): intervention group (12.92 ± 4.17); control group (13.25 ± 3.11) Sex (M/F): intervention group (10/5); control group (9/6) Dialysis duration: not reported Exclusion criteria: pregnancy; autoimmune, infectious, and cardiovascular disease; thyroid disorders; thrombocytopenia; nutritional support (central and parental nutrition)
Interventions	Intervention group L‐carnitine (oral): 50 mg/kg/day for 10 weeks Control group Placebo
Outcomes	Outcomes relevant to this review QoL (PedsQL)
Notes	Funding source: the Faculty of Nutrition and Dietetics, Tehran University of Medical Sciences
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "based on random assignment in SPSS"
Allocation concealment (selection bias)	Low risk	Quote: "sealed and uniform envelopes were then elicited by an independent coworker"
Blinding of participants and personnel (performance bias)	Low risk	Quote: "double‐blind placebo‐controlled" study
Blinding of outcome assessment (detection bias) QoL	Low risk	Quote: "double‐blind placebo‐controlled" study
Incomplete outcome data (attrition bias) QoL	Low risk	Missing outcome data balanced in numbers across intervention groups.
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported
Other bias	Low risk	Funding source: the Faculty of Nutrition and Dietetics, Tehran University of Medical Sciences