Balmer 1980.

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: Switzerland Setting: not stated Number: 40 patients Age: mean 46.2 ± 14.1 years active group; mean 52.3 ± 14.1 years placebo group Gender: 4 M:36 F Inclusion criteria: CVI without venous ulcers Exclusion criteria: varicose ulcers
Interventions	Treatment: oxirutoside 900 mg per day Control: placebo Duration: 28 days Follow‐up: 28 days Compression therapy was allowed if participants were unwilling to abandon this support
Outcomes	Primary Oedema as measured by circumference of ankle and calf (mm) Secondary Symptoms ‐ pain, cramps, tiredness, pins and needles, swelling, restless legs measured by an ordinal scale (0 to 4) Clinician's assessment Side effects
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "The trial was double‐blind, randomised, placebo controlled, between patients..." Comment: no information given about method of randomisation used
Allocation concealment (selection bias)	Unclear risk	Comment: no information given about method of treatment allocation used
Blinding (patients)	Low risk	Quote: "Patients receiving respectively the test drug or identical placebo" Comment: Identical placebo ensures double‐blinding
Blinding (study researchers)	Low risk	Quote: "Patients receiving respectively the test drug or identical placebo" Comment: Identical placebo ensures double‐blinding
Blinding (outcome assessment)	Low risk	Quote: "Patients receiving respectively the test drug or identical placebo" Comment: Identical placebo ensures double‐blinding
Incomplete outcome data	Low risk	Comment: no exclusions post randomisation and no losses to follow‐up
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