Hiatt 2011.

Study characteristics
Methods	Randomized placebo‐controlled double‐blind multi‐center trial
Participants	69 patients between 40 and 80 years with intermittent claudication minimum 1 year and peak walking time between 90 and 360 seconds at baseline were randomized (modified ITT analysis on 62 patients who got at least 1 post‐randomization treadmill test; 7 dropouts due to adverse events and study withdrawal)
Interventions	Intervention (n = 32): oral PLC 2 g/d + instruction on home‐based physical exercise 3 times weekly; duration 6 months Control (n = 30): oral placebo 2 g/d + instruction on home‐based physical exercise 3 times weekly; duration 6 months
Outcomes	Peak walking time on treadmill (speed 2 mph, slope increase 2%/2 min) Claudication onset time on treadmill (speed 2 mph, slope increase 2%/2 min)
Notes	Funding by Sigma Tau Home‐based physical exercise checked with a Stepwatch activity monitor
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information about sequence generation of parallel groups. A significant difference in proportion of diabetic patients in the subgroups was observed: fewer patients with diabetes were randomized to PLC
Allocation concealment (selection bias)	Unclear risk	No description of method of concealment
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "double‐blind study"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding of outcome assessment assumed, hence no influence on outcome assessment + several tests during double‐blind period
Incomplete outcome data (attrition bias) All outcomes	Low risk	Dropout data available; all data and P values for outcomes reported
Selective reporting (reporting bias)	Unclear risk	Limitations reported by study authors: inaccurate reporting by participants on physical exercise may lead to bias in analysis
Other bias	Unclear risk	Possible conflict of interest (funding by Sigma Tau) Quote: "there were fewer patients with diabetes randomized to PLC than placebo, P = 0.029"