Porter 1982a.
| Methods | Study design: double‐blinded, randomised Country: USA Setting: 7 centres Intention‐to‐treat: no |
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| Participants | Number of participants randomly assigned: 128 (127 + 1 randomised twice), but data presented for 124 participants (63 pentoxifylline, 61 placebo) Number of participants analysed: 82 Exclusions post randomisation: 46 Losses to follow‐up: none Age (mean): pentoxifylline: 62.0 (range 47 to 77) years, placebo: 63.5 (range 45 to 81) years Sex: pentoxifylline: 51 males, 12 females, placebo: 50 males, 11 females Inclusion criteria: IC ≥ 6 months; able to walk on treadmill ≥ 50 m at 1.5 mph; ≤ 510 m in 9.5 minutes at a speed of 2 mph before onset of claudication; stable TWD ‐ within 20% change of each other during run in phase Exclusion criteria: severe COAD with ischaemic pain at rest, ulceration, gangrene; sympathectomy within previous 6 months; severe peripheral neuropathy; chronic infection; hypersensitivity to methylxanthines (caffeine, theophylline, theobromine); women of childbearing potential/pregnant or using oral contraceptives |
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| Interventions | Treatment: oral pentoxifylline, started at 600 mg, increased gradually to 1200 mg at 1 month Control: placebo Duration: 24 weeks |
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| Outcomes | Primary: geometric mean of % change in PFWD, TWD Secondary: side effects |
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| Notes | Treadmill protocol: 1.5 mph at 7% inclination PFWD and TWD expressed as geometric mean of % change Reich 1984 presents the same study, and an ITT analysis of this study is reported in Gillings 1987 |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | States 'randomization was stratified by clinic'; no other information provided |
| Allocation concealment (selection bias) | Unclear risk | Not mentioned |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Reports the use of visibly identical placebo capsules |
| 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 appears free of other bias |