Lee 2014.

Methods	Randomised, active‐comparator controlled trial
Participants	30 participants with RLS, ages 20‐80, with serum ferritin 15‐50 ng/mL, enrolled at a single site (Korea)
Interventions	Intervention: oral ferrous sulfate, 325 mg bid, for 12 weeks Control: oral pramipexole at bedtime, starting dose 0.25 mg with dose increase as needed and tolerated
Outcomes	IRLS measured at baseline, weeks 2, 4, 8, and 12, ferritin, ESS score, Beck Depression Inventory, PSQI
Notes	The authors calculated that > 20 subjects would be needed per group for 80% power to detect an effect size of 0.8
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Block randomisation used
Allocation concealment (selection bias)	Unclear risk	No mention of allocation concealment; study unblinded
Blinding (performance bias and detection bias) All outcomes	High risk	Study was unblinded to participants and study personnel
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Although last observation carried forward was used, there was a high dropout rate for treatment‐related reasons that differed between conditions (4/15 dropped out of pramipexole group because of side effects versus 1/15 from iron group for lack of efficacy; an additional 2/15 left the iron group for study inconvenience)
Selective reporting (reporting bias)	Unclear risk	No mention of protocol registration
Other bias	Low risk	No other risks identified