De Sanctis 2002a.

Study characteristics
Methods	Study design: double‐blind, randomised Country: USA Setting: 5 centres Intention‐to‐treat: yes
Participants	Number of participants randomly assigned: 120 Number of participants analysed: 101 (56 pentoxifylline, 45 placebo) Exclusions postrandomisation: 19 Losses to follow‐up: 0 Age (mean): pentoxifylline: 63 (SD 4) years, placebo: 62 (SD 3) years Sex: male:female: pentoxifylline: 36:20, placebo: 24:21 Inclusion criteria: severe IC with TWD 50–200 m; IC > 4 months; resting Doppler ABI < 0.8; decrease in ankle pressure > 15 mmHg after standard exercise test on treadmill; aged 45–75 years; documentation of arterial stenoses, plaques and flow reduction due to arteriosclerosis by colour‐duplex imaging Exclusion criteria: presence of indication for revascularisation or angioplasty procedures; angina pectoris or myocardial ischaemia on effort at 80% of target heart rate; previous coronary or vascular surgery or angioplasty; aneurysms, congestive heart failure NYHA III–IV, renal failure (creatinine > 2 mg/dL), IDDM II; change > ± 25% during 2‐week run‐in period; arthritis or other pulmonary, cardiac or neoplastic disease or inflammatory or immunological disease
Interventions	Treatment: oral pentoxifylline, 600 mg tid Control: placebo Duration: 12 months
Outcomes	Primary: mean TWD Secondary: none
Notes	Treadmill protocol: 3 km/h at 12% inclination Mean TWD expressed in metres only Participants also took 300 mg antiplatelet medication as part of study treatment
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "patients were randomised into two treatment plans." Comment: no other information provided.
Allocation concealment (selection bias)	Unclear risk	Not mentioned.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information provided to permit judgement.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not mentioned.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information on dropouts provided other than due to low compliance.
Selective reporting (reporting bias)	Unclear risk	No information on dropouts provided other than due to low compliance.
Other bias	Unclear risk	Pentoxifylline dose unclear; study authors reported both 1600 mg and 1800 mg. Assumed 1800 mg (3 × 600 mg) was actual treatment.