1. Key study characteristics.

Study	Measure of restlessness	Comparator	IV or oral iron	Type of iron	Baseline iron status	Study population (if RLS plus another condition)	Time of assessment used
Allen 2011	IRLS	Placebo	IV	Ferric carboxymaltose	Not an inclusion/exclusion criterion (unless > 300 ng/mL); mean ferritin 40.6 ng/mL		23 days
Cho 2016	IRLS	Placebo	IV	Ferric carboxymaltose	Not an inclusion/exclusion criterion (unless > 300 ng/mL); mean ferritin 61.4 ng/mL		4 weeks
Davis 2000	Not measured	Placebo	Oral	Ferrous sulfate	Excluded if haemoglobin < 10 g/dL; mean ferritin 117.7 ng/mL		12‐14 weeks
Deng 2016	IRLS	Placebo	IV	Iron sucrose	For inclusion, serum ferritin < 200 ng/mL and transferrin saturation < 20%	Uremia on haemodialysis at least 1 year	2 weeks
Earley 2009	IRLS	Placebo	IV	Iron sucrose	Excluded if haemoglobin < 12 d/dL; mean ferritin 75.2 ng/mL		2 weeks
Grote 2009	IRLS	Placebo	IV	Iron sucrose	For inclusion, serum ferritin < 45 ng/mL		3 weeks
Lee 2014	IRLS	Pramipexole	Oral	Ferrous sulfate	For inclusion, serum ferritin 15‐50 ng/mL		12 weeks
Sloand 2004	University of Rochester	Placebo	IV	Iron dextrose	Not an inclusion/exclusion criterion; median ferritin 136.3 ng/mL	End‐stage renal disease on dialysis	2 weeks
Trenkwalder 2017	IRLS	Placebo	IV	Ferric carboxymaltose	For inclusion, serum ferritin < 75 ng/mL or both ferritin 75‐300 ng/mL and transferrin saturation < 20%		4 weeks
Wang 2009	IRLS	Placebo	Oral	Ferrous sulfate	For inclusion, serum ferritin 15‐75 ng/mL		12 weeks

IRLS: International Restless Legs Scale
 IV: intravenous