Marinello 2002.

Study characteristics
Methods	Study design: randomised, multi‐centre, double‐blind, placebo‐controlled Method of randomisation: not stated Exclusions post randomisation: none Losses to follow‐up: 21/123 (17%)
Participants	Country: Spain Setting: hospital Number: 143 patients Age: mean 52.87 (range 19 to 72) years Gender: 25 M:77 F Inclusion criteria: CVI stage CEAP III, IV and V Exclusion criteria: not stated
Interventions	Treatment: calcium dobesilate 1000 mg per day or calcium dobesilate 2000 mg per day Control: placebo Duration: 84 days Follow‐up: 84 days Elastic stockings permitted
Outcomes	Primary Symptoms ‐ heaviness and pain in the legs Signs ‐ transcutaneous PO2 and CO2 Secondary Not stated
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "In total 143 patients 123 were randomized (41 per treatment group)" Comment: no method of randomisation described
Allocation concealment (selection bias)	Unclear risk	Comment: no methods of allocation concealment described
Blinding (patients)	Low risk	Quote: "The placebo had the same characteristics which include active treatment. The oral administration was under the same conditions as the active treatment" Comment: Identical placebo ensures double‐blinding
Blinding (study researchers)	Low risk	Quote: "The placebo had the same characteristics which include active treatment. The oral administration was under the same conditions as the active treatment" Comment: Identical placebo ensures double‐blinding
Blinding (outcome assessment)	Low risk	Quote: "The placebo had the same characteristics which include active treatment. The oral administration was under the same conditions as the active treatment" Comment: Identical placebo ensures double‐blinding
Incomplete outcome data	Low risk	Comment: number of participants in each group described, along with baseline characteristics. In addition, numbers and information provided about adverse events and participants who withdrew prematurely from the study
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