Ziaee 2019.

Study characteristics
Methods	Study design: parallel RCT Study duration: not reported Follow‐up duration: 9 months
Participants	Setting: single centre Country: Iran Relevant health status: CKD‐5D on HD; serum potassium level < 5.5 mEq/L; SBP > 100 mm Hg at the beginning of the study; LVM index > 51 g/m² indexed for height; stable antihypertensive treatment in the preceding 6 months Number: treatment group (24); control group (24) Mean age ± SD (years): treatment group (69.2 ± 13.5); control group (67.5 ± 10.0) Sex (M/F): treatment group (12/10); control group (13/8) Exclusion criteria: high risk of hyperkalaemia (predialysis serum potassium level > 6 mEq/L); kidney transplantation during the study; a dialysis dose of Kt/V < 1.2; history or evidence of angina or MI, heart failure, peripheral vascular disease, previous hyperkalaemia, valvular heart disease, atrial fibrillation; Hb < 9.5 g/dL; receiving treatment with spironolactone
Interventions	Treatment group Spironolactone: 25 mg/HD for 36 weeks Control group Standard care for 36 weeks
Outcomes	Left ventricular volume EF Death (any cause) Gynaecomastia Serum potassium
Identification	Authors name: Azamolsadat Roshan Institution: Taleghani Hospital Email: shivaroshana@yahoo.com Address: not reported
Notes	Funding source: not reported Complete follow‐up: treatment group (20/24, 83.3%); control group (18/24, 75.0%)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Quote: "In the allocation of the patients to the 2 groups, those who referred on even days were assigned to the control group, and those who referred on odd days were assigned to the case group (receiving spironolactone)."
Allocation concealment (selection bias)	High risk	Quote: "In the allocation of the patients to the 2 groups, those who referred on even days were assigned to the control group, and those who referred on odd days were assigned to the case group (receiving spironolactone)."
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "The patients in the case group, after each HD session, were given 25 mg of spironolactone by a nurse, who was unaware of the grouping of the patients. Spironolactone used in this protocol was acquired on the market as Aldactone 25 mg. The patients in the second group were given no medication."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "In order to follow up the patients and measure the study variables at baseline and after 9 months, echocardiography was conducted by a single examiner, who was unaware of the study procedure and the allocation of the patients."
Incomplete outcome data (attrition bias) All outcomes	High risk	Imbalance in numbers for missing data across intervention groups
Selective reporting (reporting bias)	Unclear risk	Not reported
Other bias	Unclear risk	Funding: not reported

ACEi ‐ angiotensin converting enzyme inhibitors; ARB ‐ angiotensin receptor blockers; CKD ‐ chronic kidney disease; DBP ‐ diastolic blood pressure; EF ‐ ejection fraction; ESKD ‐ end‐stage kidney disease; (m)GFR ‐ (measured) glomerular filtration rate; Hb ‐ haemoglobin; HD ‐ haemodialysis; KtV ‐ dialysis adequacy; LVM ‐ left ventricular mass; M/F ‐ male/female; MI ‐ myocardial infarction; NYHA ‐ New York Heart Association; PD ‐ peritoneal dialysis; RCT ‐ randomised control trial; SBP ‐ systolic blood pressure