Leach 2003.

Study characteristics
Methods	Study design: split‐body, randomised study comparing sodium tetradecyl sulfate and glycerin Method of randomisation: coin toss to determine which leg was assigned each treatment (confirmed through correspondence with trial co‐author Mitchell P Goldman, MD) Blinding: patient ‐ no, doctor ‐ no Power calculation: no Number randomised: 13 patients had each lower limb randomised to receive one of two sclerosing agents Exclusions post‐randomisation: none Losses to follow up: none Source of funding: "No significant interest with commercial supporters." No funding source stated
Participants	Setting: outpatient location Country: USA Total number: 13 patients Age: mean age 57 years (range of 41 to 70) Sex: female Inclusion criteria: presence of leg veins 0.2 to 0.4 mm in diameter without evidence of feeding reticular veins Exclusion criteria: incompetence at the saphenofemoral or saphenopopliteal junctions
Interventions	Treatment: one leg of each patient was randomised to receive either sodium tetradecyl sulfate (STS) 0.25% or chromated glycerin 72%, and the other leg received the other agent Duration of follow up: ranged from 2 to 6 months
Outcomes	Efficacy: vessel clearance (yes,no) assessed by treating physician at follow up Adverse events: bruising, swelling, hyperpigmentation (yes, no) assessed by treating physician at follow up Pain: assessed by patient at time of injection (yes, no)
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	A coin toss (method confirmed through correspondence with study co‐author Mitchell P Goldman, MD).
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding (performance bias and detection bias) All outcomes	High risk	No blinding mentioned. STS and CG have different viscosities that are visible at time of injection.
Incomplete outcome data (attrition bias) All outcomes	Low risk	There were no incomplete data.
Selective reporting (reporting bias)	Low risk	All specified outcomes were reported.
Other bias	Low risk	The study appears to be free of other sources of bias.