Goldman 2002.

Study characteristics
Methods	Study design: multicentre, randomised, double‐blinded study comparing polidocanol and sodium tetradecyl sulfate Method of randomisation: coin toss (information obtained through personal correspondence with study author Mitchell P Goldman, MD) Blinding: patient ‐ yes, treating doctor ‐ yes, photographic outcome assessors ‐ yes Power calculation: not mentioned Number of patients randomised: 129 (42 with veins < 1 mm) Number of patients analysed: 129 (42 with veins < 1 mm) Number of exclusions post‐randomisation: unclear Number of withdrawals post‐randomisation: unclear Source of funding: Kreussler & Co GmbH (manufacturer of sclerosant), Beisdorf‐Jobst (manufacturer of compression hosiery)
Participants	Setting: multiple outpatient centres Country: USA Total number: 129 (42 with veins < 1mm) Age: Not mentioned Sex: Not mentioned Inclusion criteria: presence of varicose, reticular, and/or telangiectatic leg veins Exclusion criteria: incompetence at the saphenofemoral or saphenopopliteal junctions
Interventions	Treatment 1: polidocanol (veins < 1 mm 0.5%; 1 to 3 mm 1.0%; 3 to 6 mm 3%). Treatment 2: sodium tetradecyl sulfate (veins < 1 mm 0.25%; 1 to 3 mm 0.5%; 3 to 6 mm 1.5%) Duration: 16 weeks
Outcomes	1) efficacy: three vascular surgeons blinded to intervention agent assessed photographs from baseline, week 1, week 4, and week 16 on a scale of 1 to 5 2) adverse sequelae ‐ data was not separated for veins < 1mm 3) patient satisfaction ‐ data was not separated for veins < 1mm
Notes	Data was not separated for veins < 1mm for adverse sequelae or patient satisfaction.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Coin toss as per personal correspondence with Mitchell P Goldman, MD.
Allocation concealment (selection bias)	Low risk	Physician was given the solution to inject by nurse (personal communication with Mitchell P Goldman, MD).
Blinding (performance bias and detection bias) All outcomes	Low risk	Treating physician and patients were blinded to the agent being injected. Three vascular surgeons blinded to treatment and study centre evaluated photographs.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	42 patients with veins < 1mm were randomised to receive STS 0.25% or POL 0.5%. Data presented was N = 32 for the STS group and N = 26 of the POL group. No explanation was provided.
Selective reporting (reporting bias)	High risk	Not all outcome data was separated based on vein size. Patient satisfaction data was mentioned only in the abstract, and not described in the methods or results section. As addressed in assessment of incomplete outcome data, it is unclear if the low number of veins treated in each group are related to missing data or to baseline asymmetry of vein presence on each patient's legs. Unsuccessful in attempt to clarify this discrepancy via communication with study author.
Other bias	Unclear risk	The study was partly funded by Kreussler & Co GmbH (manufacturer of sclerosant) and Beisdorf‐Jobst (manufacturer of compression hosiery).