Beduschi 2013.

Methods	Study design: parallel RCT Duration of study (recruitment): April 2007 to February 2009 Duration of follow‐up: 16 weeks
Participants	Country: Brazil Setting: single centre Adults ≥18 years on HD with a vintage of ≥ 90 days at enrolment, treated previously with standard dialysate [Na+] of 138 mM Number (randomised/analysed): treatment group (29/20); control group (23/18) Mean age ± SD (years): treatment group (64.95 ± 14.02); control group (60.22 ± 13.96) Sex (M/F): treatment group 14/6; control group (10/8) Mean time on dialysis; IQR (months): treatment group (30.9; 19.5, 75.0); control group (49.5; 26.0, 58.0) Measured characteristics and comorbidities otherwise balanced Exclusion criteria: acute inflammatory processes; chronic inflammatory diseases; antibiotic use within the past 2 months; malignancies; central venous catheter use
Interventions	HD regimen 3 times/week, 3.5 to 4 hours/session Low‐flux polysulfone dialyser Bicarbonate‐buffered dialysate Prescribed Kt/V at least 1.4 Treatment group Dialysate [Na+]: 135 mM Control group Dialysate [Na+]: 138 mM Duration 16 weeks (864 HD sessions in control group, 960 in treatment group)
Outcomes	Outcomes were assessed at 8 and 16 weeks, with BP and IDWG being assessed as the mean of the last 10 preceding sessions Predialysis SBP Predialysis DBP Predialysis MAP Postdialysis MAP Intradialytic hypotension: "defined as the presence of BP levels lower than 90 x 60 mmHg" Intradialytic cramps IDWG Predialysis serum [Na+] Postdialysis extracellular fluid volume status: multipolar bioimpedance analysis Dietary salt intake: 3‐day food diary Other biochemical measurements
Notes	Funding source: FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo). Extra information was requested and supplied in full from authors (all emails on file) SD for IDWG instead of IQR Pre‐ and postdialysis MAP (mean and SD) % of treatments (rather than of patients as reported) with intradialytic cramps or hypotension. Presence and extent of blinding An error in the paper with respect to the reporting of dietary sodium intake between groups, where the daily sodium intake (g/d) was at the end of these study was 8.71 (0.8) in group A and 9.24 (1.28) in group B. This was confirmed with the authors and should have been reported as salt intake per day, and equates to a sodium intake (g/d) of 3.43 (0.3) in group A and 3.64 (0.5) in group B.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation clearly stated in published article, along with mechanism of randomisation
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Patients not blinded, although outcomes are unlikely to be biased by their nature
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	14/52 (27%) participants were withdrawn because of acute infections during the study period, 9 from the treatment group and 5 from the control group. The study is not analysed as intention to treat, and data from those who dropped out are omitted from analysis. Although the reasons for dropout do not appear to be related to the treatment, there is still a possibility of attrition bias. In addition, this large number of dropouts may have affected balance of patient characteristics by arm. The groups appeared balanced on measured confounders in Table 1, but an effect of these dropouts on unmeasured confounders is unknown
Selective reporting (reporting bias)	Low risk	The study appears to be free of reporting bias
Other bias	Low risk	The study appears to be free of other sources of bias