Puggina 2020.

Study characteristics
Methods	Study design: prospective, randomised, single study Study grouping: parallel Ethics and informed consent: yes Follow‐up period: 1 year Sample size estimate: yes ITT analysis: yes, number randomised: 56, number analysed: 56 Funding: government research funding agency (São Paulo Research Foundation – FAPESP) Preregistration: yes
Participants	Location: Brazil Intervention group: n = 27, control group: n = 29 Mean age (SD): RFA group 53.48 (± 12.73); Control group 54.06 (± 11.70) Inclusion criteria: participants between the ages of 18 and 80 with an active venous leg ulcer presented for more than 4 weeks, ABPI > 0.8 and either long or short or both saphenous vein incompetence. Exclusion criteria: people with evidence of significant arterial obstruction (ABPI < 0.8); previous history or current evidence of occlusion/obstruction and previous deep venous thrombosis in the index leg; evidence of previous superficial thrombophlebitis in the target saphenous vein; pregnancy; contraindications for surgery even under local anaesthetic; other causes of ulceration in legs; inability to walk or severe ankle ankylosis; no evidence of insufficiency of at least 1 saphenous vein and 1 perforating vein in the index leg; saphenous vein diameter > 12 mm.
Interventions	Aim/s: to investigate whether RFA of insufficient saphenous and perforating veins could prevent VLU recurrence and increase healing rates. Group 1 (RFA group) intervention: RFA of insufficient saphenous and perforating veins followed by compression using a two‐layer compressive system changed weekly. Group 2 (control group) intervention: compression alone treatment using a two‐layer compressive system changed weekly. Study date/s: January 2015 to August 2017
Outcomes	Ulcer recurrence rate Ulcer healing rate Ulcer healing velocity Validity of measure/s: superficial venous reflux predefined, ulcer healing predefined. Time points: 6 weeks, 12, weeks, 24 weeks, 52 weeks (1 year)
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	An independent remote computerised randomisation service.
Allocation concealment (selection bias)	Low risk	Use of sealed, opaque, sequentially numbered envelopes.
Blinding of participants and personnel (performance bias) All outcomes	High risk	As blinding was not possible, performance bias may have occurred. It should be noted that it is not reasonably possible to blind treating clinicians or participants in trials of this nature in an ethical context.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The ultrasound evaluation before and after treatment was performed by an independent physician who had no information about participants' treatment and outcome.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only one dropout in control group.
Selective reporting (reporting bias)	Low risk	Prespecified protocol and subgroup analysis.
Other bias	Low risk	No other biases detected.

ABPI: ankle brachial pressure index; RFA: radiofrequency ablation; VLU: venous leg ulcer