O'Donnell 2009.

Study characteristics
Methods	Study design: single‐centre, randomised, double‐blind, placebo‐controlled Intention‐to‐treat: yes Country: Northern Ireland
Participants	Number randomised: 106 (cilostazol n = 51; placebo n = 55) Age (median years): cilostazol = 64.2; placebo = 66.1 Sex (M/F): cilostazol = 34/17; placebo = 39/16 Inclusion criteria: aged 30 to 90 years (both sexes); had PAD with IC with an ABI < 0.9 stable on optimal medical therapy for 3 months Exclusion criteria: current or previous acute or critical limb ischaemia; severe claudication prohibiting treadmill testing; endovascular or surgical procedures within the preceding 6 months; non‐atherosclerotic comorbidity that had limited their walking before the onset of claudication pain; predisposition to bleeding; a history of uncontrolled cardiac, respiratory, renal or liver disease; use of omeprazole or diltiazem
Interventions	Treatment: cilostazol 100 mg, twice daily, oral route Control: placebo, twice daily, oral route Duration: 24 weeks
Outcomes	ICD, ACD, oxygen‐derived free‐radical generation, antioxidant consumption, other inflammatory cascade markers, QoL (SF‐36, WIQ, VascuQol); measured at baseline and weeks 6 and 24
Funding	Otsuka America Pharmaceutical Inc. provided the placebo. The study was funded by the Belfast City Hospital Vascular Research Fund and the Daisy Hill Hospital research fellowships and research grants from the Insulin Dependant Diabetes Trust and the Royal College of Surgeons Edinburgh.
Declaration of interests	Otsuka America Pharmaceutical Inc. provided the placebo for use in the study. Dr O’Donnell has received financial support from Otsuka Pharmaceuticals for travel costs to attend conferences to present data from this clinical trial.
Notes	Calibrated treadmill test with a constant speed of 3.2 km/h and constant 10% gradient Four‐week stabilisation run‐in period
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Patient‐treatment randomisation and allocation was performed independently by the Department of Research Pharmacology in the Belfast City Hospital". Insufficient information on sequence generation
Allocation concealment (selection bias)	Low risk	"Both, the patient and the primary investigator, were blinded to study‐drug allocation, which was completed using the sealed‐envelope method".
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Both, the patient and the primary investigator, were blinded to study‐drug allocation". "Study‐drug un‐blinding was performed at the end of the study, following the completion of all clinical assessments and laboratory analyses for all patients".
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding of assessors not adequately discussed
Incomplete outcome data (attrition bias) All outcomes	Low risk	Dropouts were similar between treatment groups.
Selective reporting (reporting bias)	Low risk	Although no study protocol was available, all outcomes appeared to be reported on.
Other bias	Low risk	No evidence of other bias