West 2011.

Methods	Design: single‐centre, prospective, double‐blind, randomised trial Number of study centres: single‐centre in the USA Setting: not reported Patient recruitment: 2/1/2006 to 9/20/2007 Duration of study: 2 years Clinical setting: peripheral arterial disease
Participants	Enrolment (N): 87 Randomised (N): intervention: 22; control: 22 Withdrawn (N): not reported Lost to follow‐up (N): intervention: 1; control: 3 Completed the study (N): intervention: 18; control: 16 Analysed (N): intervention: 18; control: 16 Age (years) (mean ± SD): intervention: 62 ± 8; control: 59 ± 10 Sex (male, N, %): intervention: 10 (56%); control: 11 (69%) Smoking history (N, %): intervention: 13 (72%); control: 8 (50%) BMI (kg/m², mean ± SD):): intervention: 28 ± 6; control: 30 ± 7 Diabetes (N, %): intervention: 5 (28%); control: 5 (31%) Hypertension (N, %): intervention: 14 (78%); control: 13(81%) History of MI (N, %): intervention: 10 (56%); control: 8 (50%) Statin pretreatment (N, %): intervention: 6 (33%); control:2 (13%) Inclusion criteria: Statin‐naive patients (no statin therapy for at least the prior 6 months) between the ages of 30 and 85 years with symptoms of intermittent claudication and an ankle‐brachial index (ABI) between 0.4 and 0.9, based on vascular lab testing done during the screening period Exclusion criteria: rest pain, critical limb ischaemia, contraindication to MRI, and pregnancy.
Interventions	Intervention: combination of simvastatin 40 mg plus ezetimibe 10 mg daily (group S + E) . Comparison: simvastatin 40 mg (group S). Tthe parallel direct treatment study, patients were enrolled already on statin therapy but with LDL‐C > 80 mg/dL and had open‐label ezetimibe 10 mg daily added (group E). Details of any 'run‐in' period: none
Outcomes	Primary: changes in superficial femoral artery vessel wall volume measured by magnetic resonance imaging (MRI); total cholesterol, HDL‐C, LDL‐C, triglycerides; adverse events; major adverse cardiovascular events, including death, MI, stroke, and transient ischemics attack.
Notes	Funding: This work was supported by the National Heart Lung and Blood Institute at the National Institutes of Health, grant number: R01HL075792 (CMK) and the National Center for Research Resources, grant number: M01RR000847 and the National Institute of Biomedical Imaging and Bioengineering, grant number: T32 EB003841 (JDA, AMW). Study drugs were supplied by Merck Schering Plough.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Used a block randomisation scheme.
Allocation concealment (selection bias)	Low risk	Used a block randomisation scheme.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	The investigators were blinded to therapy until follow‐up studies and data analysis were complete. The study stated Quote: "double‐blind, randomized trial", but did not use the matching placebo for ezetimibe.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The plaque volume analysis was done primarily by two experienced investigators blinded to study drug and time point with VesselMASS software." Quote: "The blinded studies were all overseen and validated by one investigator."
Incomplete outcome data (attrition bias) All outcomes	High risk	Proportion of missing data: 18% (4/22) in intervention group, 27% (6/22) in control group
Selective reporting (reporting bias)	Low risk	No protocol published, but a pre‐registration in a clinical trial registry was found (NCT00861731). The published reports include all prespecified outcomes.
Other bias	Low risk	Quote:"This work was supported by the National Heart Lung and Blood Institute at the National Institutes of Health." Quote:"Study drugs were supplied by Merck Schering Plough." "Drs. Epstein, Meyer, Hagspiel, and Kramer receive research support from Siemens Medical Solutions. All other authors have no declared conflicts of interest."