Pilz 1990.

Methods	Study design: 2 parallel arms, randomised, double‐blind. Method of randomisation: block randomisation. Exclusion post randomisation: two. Losses to follow up: none. Quality score = 4.
Participants	Country: Germany. Setting: GP practice. No: 30 entered, 2 drop outs. Age: (mean) 46 in total patient sample. Sex: males 6; females 24. Inclusion criteria: Symptoms of CVI with peripheral leg oedema. Exclusion criteria: patients under 20 and over 70 years of age, less than 2 symptoms of CVI, leg ulcers, oedema or leg pain of other origin than CVI, rheumatic diseases, concomitant medication, compression treatment.
Interventions	Treatment: 1 capsule HCSE (standardised to 50 mg escin) twice daily. Control: placebo. Duration: 20 days.
Outcomes	Primary: (not explicitly stated). Secondary: (not explicitly stated).
Notes	Standardised mean difference (95% CI): Primary: circumference (mm). a) ankle 0.70 (‐0.04 to 1.45) b) calf 0.86 (0.11 to 1.61) Secondary: (not explicitly stated) adverse events. none.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	Block randomisation and allocation of patients to treatment and control groups was performed centrally by Klinge Pharma. The random code was stored in sealed envelopes.
Blinding (performance bias and detection bias) All outcomes	Low risk	Verum and placebo were indistinguishable in terms of outer appearance and taste
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	It is unclear how incomplete outcome data were addressed
Selective reporting (reporting bias)	Low risk	No evidence of selective reporting
Other bias	Unclear risk	No evidence of other biases