Ni 2014.

Study characteristics
Methods	Study design: parallel RCT Study duration: not reported Follow‐up period: 12 weeks
Participants	Setting: multicentre (2 sites) Country: China Relevant health status: CKD‐5D on HD or PD; refractory hypertension Number: treatment group (40); control group (36) Mean age ± SD (years): treatment group (55.7 ± 12.3); control group (54.9 ± 14.2) Sex (M): treatment group (60.0%); control group (58.3%) Exclusion criteria: prior use of spironolactone; potassium level > 5 mmol/L
Interventions	Treatment group Spironolactone: 25 mg/day for 12 weeks Control group Placebo for 12 weeks
Outcomes	Serum potassium Residual kidney function: urine volume
Identification	Authors name: Xiaoying Ni Institution: Department of Nephrology, People’s Hospital of Yinzhou, College of Medicine, Ningbo University Email: jishengz2013@163.com Address: Ningbo, Zhejiang, PR China
Notes	Funding source: not reported Complete follow‐up: treatment group (36/40, 90.0%); control group (34/36, 94.4%)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Only states the study was randomised, does not ensure how sequence generation was done
Allocation concealment (selection bias)	Unclear risk	Only states the study was randomised, does not ensure how sequence generation was done
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"double‐blind" study
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"double‐blind" study
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing outcome data balanced across intervention groups.
Selective reporting (reporting bias)	Unclear risk	Protocol unclear
Other bias	Unclear risk	Funding: not reported