Donaldson 1984.

Study characteristics
Methods	Study design: double‐blind, randomised Country: UK Setting: single centre Intention‐to‐treat: not mentioned
Participants	Number of participants randomly assigned: 80 (40 each group) Number of participants analysed: not mentioned Exclusions postrandomisation: 0 Losses to follow‐up: 7 Age (mean): pentoxifylline: 58.2 (SD 11.7) years, placebo: 58.9 (SD 9.1) years Sex: 31 males, 9 females in each group Inclusion criteria: typical IC pain Exclusion criteria: rest pain (or incipient gangrene); severe ischaemic heart disease; postural hypotension; receiving any drugs likely to alter claudication distance within 4 weeks before inclusion in study
Interventions	Treatment: oral pentoxifylline, 200 mg tid Control: placebo Duration: 8 weeks
Outcomes	Primary: mean PFWD, TWD Secondary: ABI, side effects
Notes	Treadmill protocol: 4 km/h at 0% inclination Mean PFWD and TWD expressed in metres only
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomised." 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	Low risk	No incomplete outcome data.
Selective reporting (reporting bias)	Unclear risk	Protocol not available; insufficient information available to permit judgement.
Other bias	Low risk	Study appeared free of other bias.