Ihme 1996.

Study characteristics
Methods	Study design: randomised, double‐blind, placebo‐controlled Method of randomisation: Rancode computer software Exclusions post randomisation: none Losses to follow‐up: 11/77 (14%)
Participants	Country: Germany Setting: hospital Number: 77 patients Age: mean 57.3 ± 9.6 years active group; mean 59.8 ± 7.3 years placebo group Gender: 24 M:53 F Inclusion criteria: CVI stages I and II (oedema, symptoms, stem varicosis, post‐thrombotic syndrome, valvular insufficiency of the deep veins) Exclusion criteria: varicosis with surgical indication; active or healed ulcus cruris; acute thrombosis or venous inflammation; oedema due to cardiac or renal insufficiency; treatment with a diuretic, dihydroergotamine or any other drugs for venous therapy; other severe disorder
Interventions	Treatment: Buckwheat herb tea (rutoside) 270 mg per day Control: placebo Duration: 90 days Follow‐up: 112 days
Outcomes	Primary Signs ‐ oedema, lower leg volume of more seriously affected leg by a Gutmann volumeter and ultrasound Secondary Symptoms ‐ tenseness, heaviness, swelling by an ordinal scale (0, 1, 2). Pain, paraesthesia, cramps, burning feet, restless legs by an ordinal scale (0, 0.5, 1) Side effects
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The randomisation was carried out by Rancode computer software (IDV Gauting, Germany)" Comment: Randomisation seems like a fair method to ensure a random sequence of participants
Allocation concealment (selection bias)	Unclear risk	Comment: no methods of allocation concealment described
Blinding (patients)	Low risk	Quote: "A blinded taste test with pharmacists demonstrated that the teas were similar in taste and appearance and hard to distinguish" Comment: Identical placebo ensures double‐blinding
Blinding (study researchers)	Low risk	Quote: "A blinded taste test with pharmacists demonstrated that the teas were similar in taste and appearance and hard to distinguish" Comment: Identical placebo ensures double‐blinding
Blinding (outcome assessment)	Low risk	Quote: "A blinded taste test with pharmacists demonstrated that the teas were similar in taste and appearance and hard to distinguish" Comment: Identical placebo ensures double‐blinding
Incomplete outcome data	Low risk	Comment: number of participants in each group described. Number of drop‐outs and reasons for dropping out of the trial described. ITT analysis conducted
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