Burnand 1989.

Study characteristics
Methods	Study design: randomised, double‐blind, placebo‐controlled Method of randomisation: not stated Exclusions post randomisation: none Losses to follow‐up: none
Participants	Country: UK Setting: hospital Number: 49 patients Age: mean 53 years Gender: 18 M:31 F Inclusion criteria: venous reflux by volumetry, with varicose veins and lipodermatosclerosis Exclusion criteria: patients with ankle‐to‐arm arterial Doppler pressure ratio < 1.0 (significant arterial disease)
Interventions	Treatment: oxerutin (Paroven) 500 mg per 12 hours Control: placebo Duration: 30 days Follow‐up: 30 days
Outcomes	Primary Signs ‐ oedema (foot volumes) measured by water displacement, transcutaneous oximetry (TCPO2) Secondary Not stated
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "A double‐blind controlled trial was undertaken.." and "the two groups of patients were balanced and randomized by trial number so that as far as possible an equal number in each group..." Comment: no details of randomisation method provided
Allocation concealment (selection bias)	Unclear risk	Comment: no methods of allocation concealment described
Blinding (patients)	Low risk	Quote: "Were given Paroven 500 mg bd or identical placebo" Comment: Identical placebo ensures double‐blinding
Blinding (study researchers)	Low risk	Quote: "Were given Paroven 500 mg bd or identical placebo" Comment: Identical placebo ensures double‐blinding
Blinding (outcome assessment)	Low risk	Quote: "This code was not broken until the completion of the study" Comment: outcome assessors blinded
Incomplete outcome data	Low risk	Comment: neither exclusions post randomisation nor losses to follow‐up described
Selective reporting	Low risk	Comment: no published protocol identified, and no differences between outcomes reported in the methods section and those reported in the results section
Other bias	Low risk	Comment: none detected