VENOUS 2020.

Study characteristics
Methods	Study design Parallel RCT Study dates Duration of follow‐up: 12 months Time frame: not reported
Participants	Study characteristics Setting: not reported Country: Japan Inclusion criteria: dialysis patients > 70 years Exclusion criteria: hypoalbuminaemia as less than 3.0 g/dL; history of cardiovascular events 3 months prior to the entry; independence; > 90 years Baseline characteristics Number (analysed/randomised): intervention group (15/28); control group (14/26) Mean age ± SD (years): not reported Sex (M/F): not reported Dialysis type: not reported Dialysis vintage (years) (mean ± SD): not reported Comorbidities CVD: intervention group (0/28); control group (0/26) Diabetes: not reported Hypertension: not reported Depression (clinician diagnosis): not reported
Interventions	Intervention classification Pharmacological intervention Indication: study reporting fatigue Intervention group Anti‐thrombotic polymethyl‐methacrylate membrane Control group Placebo Co‐interventions Not reported
Outcomes	Outcomes reported Fatigue outcome measures used: validation data available Nutritional status Malnutrition inflammation score: every 3 months, up to 12 months Normalised protein catabolic rate: every 3 months, up to 12 months Creatinine generation rate: every 3 months, up to 12 months Patients symptoms as a QoL (arthralgia, skin itchiness, irritable sense, fatigue, headache, dialysis‐related hypotension, leg cramps, and post‐dialytic bed‐free time): every 3 months, up to 12 months
Notes	Additional information Funding: not reported Conflicts of interest/disclosures: not reported Trial registration identification number: not reported A priori published protocol: not reported Abstract
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Sequence generation methods were not reported in sufficient detail to permit judgement
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment was not reported in sufficient detail to permit judgement
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not reported. However, interventions were different and participants and/or investigators could be aware of the treatment assigned
Blinding of outcome assessment (detection bias) All outcomes	High risk	It was unclear if fatigue was assessed with an appropriate measure. However, subjective measures were used, it was not stated whether outcomes were assessed without knowledge of treatment allocation, and knowledge of treatment assignment may have influenced reporting. Participant beliefs about the superiority/inferiority of either intervention could have influenced their assessment of the outcome, but there was no evidence that this was likely. Other subjective outcomes were assessed
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "11 patients in the NF group and 10 patients in the PS group were dropped out from the study. The reasons of the discontinuation were hypoalbuminaemia (1), increased bete‐2 microglobulin, social reasons (2), dead (1), unknown reason (5) in NF group, and modality change (2), unknown reason (8). Finally, 15 patients in NF and 14 patients terminated the study, however, 2 patients with the data deficit in each group were excluded."
Selective reporting (reporting bias)	High risk	Information about the protocol and the statistical analysis plan were not reported. Fatigue was reported in a format that was not extractable for meta‐analysis. All outcomes that should be addressed (fatigue, cardiovascular disease, and death) were not reported
Other bias	Unclear risk	No data were available to assess the possible imbalance between groups. Funding and conflicts of interest were not reported