Van Veldhuisen 2017.

Methods	RCT; parallel‐group (phase III). Participants were enrolled from 28 sites across 9 countries.
Participants	Participants were diagnosed with systolic heart failure, and were treated in an outpatient setting. Participants were required to have iron deficiency as determined by a serum ferritin < 100 ng/mL, or 100‐300 ng/mL where TSAT < 20%. Anaemic patients were not specifically excluded, but the mean Hb of the intervention and control groups was > 120 g/L.
Interventions	Participants were randomised to receive IV iron (ferric carboxymaltose) using a bespoke dosing strategy based on Hb and body weight (500‐1000 mg) with repeat dosing at 6 and 12 weeks, or to placebo (equivalent dose of 0.9% sodium chloride).
Outcomes	Primary endpoint was change in VO2 peak from baseline to week 24. Secondary endpoints includes effects on Hb, ferritin, TSAT and cardiac biomarkers, QoL and safety endpoints.
Study funding arrangements	The study was sponsored by Vifor Pharma, Switzerland. The lead author is an Established Investigator of The Netherlands Heart Foundation.
Author conflicts of interest	Multiple study authors received research funding, consultancy fees or honoraria from Vifor Pharma Pty Ltd. Two study authors are employees of Vifor Pharma Pty Ltd.
Sample size	A total of 172 participants were studied and randomised 1:1 to receive the intervention (n = 86) or the control (n = 86) treatment.
Notes	Study was registered with a public trials register (NCT 01394562).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: no information is given on the process of randomisation or sequence generation.
Allocation concealment (selection bias)	Unclear risk	Comment: no information is given on processes or means of ensuring allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment: this was an open‐label study. Participants and site personnel were not blinded to the group allocation or the intervention
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: whilst VO2 peak was assessed at central laboratory, the clinicians performing the test itself were not blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: reasons for exclusions were clearly stated, and both full analysis set and per protocol analyses were performed.
Selective reporting (reporting bias)	Unclear risk	Comment: whilst there was complete outcome reporting, some data (notably TSAT and ferritin) were reported as medial only, with no IQR or other variability data included.
Other bias	High risk	Comment: the study was sponsored by Vifor Pharma Pty Ltd, and multiple authors accepted funding from Vifor Pharma Pty Ltd, or are employees of Vifor Pharma Pty Ltd.