MacLennan 1994.

Study characteristics
Methods	Study design: multicenter, international, parallel, randomised, double‐blind, placebo‐controlled trial Method of randomisation: not stated Exclusions post randomisation: none Losses to follow‐up: 16/104 (15%)
Participants	Country: UK, Germany, Netherland and Belgium Setting: hospital Number: 104 patients Age: ≥ 65 years Gender: 24 M:62 F Inclusion criteria: unilateral or bilateral symptoms and signs of CVI. Compression stockings allowed Exclusion criteria: bed‐bound or with cardiac or renal or hepatic disease or clinically important obesity; arterial insufficiency of the legs
Interventions	Treatment Oxirutoside 900 mg per day for 180 days Oxirutoside 1000 mg per day for 180 days Oxirutoside 1200 mg per day for 180 days Placebo for 180 days Follow‐up: 180 days Participants who wore elastic support stockings had to continue to wear them throughout the study
Outcomes	Primary Oedema, by reduction of leg volume Symptoms ‐ tenseness, heaviness, swelling, pain, paraesthesia, cramps, burning feet, restless legs and itching Secondary Side effects
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization was made according to a computer‐generated randomization list in blocks of 10" Comment: computer‐generated randomisation list generally accepted as an appropriate way to generate a random sequence of participants
Allocation concealment (selection bias)	Unclear risk	Comment: no method of allocation concealment stated
Blinding (patients)	Low risk	Quote: "Patients from each centre in the randomised control group were given placebo capsules identical in appearance" Comment: Identical placebo ensures double‐blinding
Blinding (study researchers)	Low risk	Quote: "Patients from each centre in the randomised control group were given placebo capsules identical in appearance" Comment: Identical placebo ensures double‐blinding
Blinding (outcome assessment)	Low risk	Quote: "Patients from each centre in the randomised control group were given placebo capsules identical in appearance" Comment: Identical placebo ensures double‐blinding
Incomplete outcome data	Low risk	Comment: number of participants described, along with the most important characteristics, number of drop‐outs, adverse events and information on compliance
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