Lindgarde 1989.

Study characteristics
Methods	Study design: double‐blind, randomised Country: Scandinavia Setting: multi‐centre Intention‐to‐treat: yes
Participants	Number of participants randomly assigned: 150 (76 pentoxifylline, 74 placebo) Number of participants analysed: 150 Exclusions postrandomisation: 0 Losses to follow‐up: 0 Age (mean): pentoxifylline: 65 (SD 7) years, placebo: 64 (SD 8) years Sex: pentoxifylline: 79% males, placebo: 80% males Inclusion criteria: aged ≥ 40 years; moderate‐to‐severe COAD; initial claudication distance 50–200 m; claudication history > 6 months; variance of walking distance < 35% in the last 2 treadmill tests with baseline walking distance < 100 m; variance of walking distance < 25% in the last 2 treadmill tests with baseline walking distance 101–200 m Exclusion criteria: complete occlusion of the aortoiliac segment, the femoral bifurcation or the popliteal artery without angiographically confirmed distal refilling of the respective segment; vascular reconstruction of sympathectomy within the past 12 months; peripheral neuropathy; Buerger's disease; marked postphlebotic syndrome; diabetes; cardiac failure or severe rhythm disorders; major infections; abnormal values for platelets; history of xanthine hypersensitivity; addiction to analgesics; malignant disease
Interventions	Treatment: oral pentoxifylline, 400 mg tid Control: placebo Duration: 6 months
Outcomes	Primary: geometric means of % change in TWD and PFWD from baseline to follow‐up Secondary: ABI, side effects
Notes	Treadmill protocol: 3.2 km/h at 12.5% inclination PFWD and TWD expressed as geometric mean of % change
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomisation stratified by centres." Comment: no other information provided.
Allocation concealment (selection bias)	Unclear risk	Not mentioned.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "During the double‐blind period and according to a randomization plan, pentoxifylline or matching placebo was administered t.i.d. [tid]"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not mentioned.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	ABI data not provided for the main analysis.
Selective reporting (reporting bias)	Unclear risk	ABI data not provided for the main analysis.
Other bias	Low risk	Study appeared free of other bias.