Dominguez 1992.

Study characteristics
Methods	Study design: randomised, double‐blind, placebo‐controlled Method of randomisation: computer‐generated random number table Exclusions post randomisation: none Losses to follow‐up: 7/57 (12%)
Participants	Country: Spain Setting: hospital Number: 57 patients Age: 20 to 65 years Gender: 5 M:52 F Inclusion criteria: symptomatic CVI and varicose veins and oedema Exclusion criteria: elastic bandages, anti‐inflammatory drugs and diuretics not permitted. Surgical operation, thrombophlebitis, pregnancy, diabetes, cardiopathy, hepatopathy, nephropathy, varicose veins secondary to extrinsic compression and varicose ulcers excluded
Interventions	Treatment: hidrosmine 600 mg per day Control: placebo Duration: 45 days Follow‐up: 45 days
Outcomes	Primary Symptoms ‐ heaviness, pain and cramps measured by an ordinal scale (0 to 9); pruritus and cramps measured by a semiquantitative scale (0 to 3); ankle swelling, measure of narrowest section by photogram Secondary Side effects
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "On entry, patients were assigned to one or other of the two treatment groups according to a computer‐generated random number table" Comment: computer‐generated random number table considered a fair method to ensure good randomisation
Allocation concealment (selection bias)	Unclear risk	Comment: no methods of allocation concealment described
Blinding (patients)	Low risk	Quote: "The medications were supplied in identical capsule form" Comment: Identical placebo ensures double‐blinding
Blinding (study researchers)	Low risk	Quote: "The medications were supplied in identical capsule form" Comment: Identical placebo ensures double‐blinding
Blinding (outcome assessment)	Low risk	Quote: "The medications were supplied in identical capsule form" Comment: Identical placebo ensures double‐blinding
Incomplete outcome data	Low risk	Comment: number of participants in each group reported, along with information on compliance, drop‐outs (7/57; 12%), reasons for drop‐out and adverse events. 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