Lynch 2012.

Methods	Double‐blind, placebo‐controlled, randomised trial involving 3 treatment arms (placebo, low‐dose α‐tocopheryl quinone (510 mg/day) or high‐dose α‐tocopheryl quinone (EPI‐A0001) (750 mg/day))
Participants	31 participants with genetically confirmed Friedreich ataxia aged between 18 and 60 years. 10 participants were randomised into the placebo arm, 11 into the low‐dose α‐tocopheryl quinone arm and 10 into the high‐dose α‐tocopheryl quinone arm
Interventions	Participants received capsules containing either 250 mg or 170 mg of α‐tocopheryl quinone in olive oil 3 times daily with meals. The placebo group received identical capsules containing 0.01% beta‐carotene in olive oil. Treatment was provided for 28 days
Outcomes	Outcomes were measured at baseline, at 14 days of treatment and at 28 days of treatment. The primary study outcome was a measure of diabetic tendency. Secondary outcome measures included the FARS and SF‐36
Notes	The Friedreich Ataxia Research Alliance and Penwest Pharmaceutical provided funding Authors Lynch and Willi received grant support from Penwest Pharmaceutical to undertake the study. Authors Hawi and Sciascia were employed by Penwest during the study. Authors Miller and Shrader held stock in Edison Pharmaceuticals (owner of EPI‐A0001). Author Miller was an employee and received 100% of his compensation from Edison Pharmaceuticals. Author Shrader was a compensated consultant for Edison Pharmaceuticals. Author Rioux had been previously employed by Edison Pharmaceuticals. Provider of the drug for this study is not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	The method of randomisation is not clear and did not completely match the 3 groups. The placebo group had higher clinical severity scores
Allocation concealment (selection bias)	Unclear risk	The method of allocation concealment is not clear
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants were blinded to the treatment by the use of identical capsules for α‐tocopheryl quinone and placebo
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	It is not clear how examiners were blinded to the treatments
Selective reporting (reporting bias)	Low risk	All planned outcomes were reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	One participant from the high‐dose α‐tocopheryl quinone arm discontinued treatment due to a major protocol violation
Other bias	Low risk	None identified