Vanscheidt 2002a.

Study characteristics
Methods	Study design: randomised, double‐blind, placebo‐controlled trial Method of randomisation: not stated Exclusions post randomisation: none Losses to follow‐up: 52/231 (22.5%)
Participants	Country: Germany Setting: university Number: 231 patients Age: mean 55.1 (range 23 to 78) years Gender: 48 M:183 F Inclusion criteria: stages 3 to 5 of CEAP Exclusion criteria: surgical treatment of CVI; heart insufficiency; arterial occlusive disease; diabetes mellitus; neuropathy; acute thrombosis; lymphoedema; renal insufficiency or impaired liver function; malignant disease; pregnancy or breast feeding; major surgery; drugs with influence on the veins
Interventions	Treatment: SB‐LOT (15 mg coumarin and 90 mg troxerutin) 2 tablets 3 × per day for 16 weeks Control: placebo Duration: 112 days Follow‐up: 112 days All participants received standard compression stockings during first 4 weeks
Outcomes	Primary Differences in lower leg volume after completion of treatment period as compared with baseline, measured by water displacement plethysmometry Secondary Tired legs, heavy legs, feeling of tension, feeling of swelling, aching, itching, burning, quality of life (EUROQOL), Clinical Global Impression
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The randomisation schedule was generated by the validated PC programme RanCode plus, independently to all study participants. It was based on blocks of 4 patients. All medication was pre‐numbered and distributed to the centres" Comment: computer‐generated table of random numbers ensures a random sequence of participants
Allocation concealment (selection bias)	Low risk	Quote: "Patients were included in the study by receiving the next consecutive random number. For each patient the study centres were supplied sealed envelopes with the treatment group information" Comment: sealed envelopes and allocation of participants by giving the next consecutive random number ensure fair allocation concealment
Blinding (patients)	Low risk	Quote: "Placebo tablets matched the active tablets in taste, smell and appearance" Comment: Identical placebo ensures double‐blinding
Blinding (study researchers)	Low risk	Quote: "Placebo tablets matched the active tablets in taste, smell and appearance" Comment: Identical placebo ensures double‐blinding
Blinding (outcome assessment)	Low risk	Quote: "Placebo tablets matched the active tablets in taste, smell and appearance" Comment: Identical placebo ensures double‐blinding
Incomplete outcome data	Low risk	Comment: number of participants in each group described, along with the most important characteristics and inclusion and exclusion criteria. In addition, study author stated the number of participants who withdrew from the study prematurely or were excluded after randomisation (22.5%). ITT analysis conducted
Selective reporting	Low risk	Comment: no 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