Makarova 2001.

Methods	Study design: randomised, parallel trial Method of randomisation: not stated. Patients treated by elasticated compression for 5 years before study and divided into stable (unchanging CEAP clinical class) and progressive (deteriorating CEAP class) on entry into study Blinding not stated Exclusions post randomisation: not stated Exclusions for failure to consent: 40 Dropouts (lost to follow‐up): 3 Duration of study (postoperatively): 7 years Comparable treatment and control groups
Participants	Country: Russia No: 168 participants entered. 149 completed 5‐year observation period. 19 refused surgery. 128 entered surgical period. 125 completed 7 years of follow‐up (63 treatment, 62 control) Age: not stated Sex: not stated Inclusion criteria: CEAP C2 to C4 Ultrasound reflux in both GSV and SFV Exclusion criteria: history of DVT, episodes of acute oedema of lower extremity, trauma, major surgery, hospital stay with bed rest longer than 3 days. Ultrasound findings (confirmed on phlebography) of occlusion/stenosis of femoral vein or massive collateral venous pathways
Interventions	Treatment: unilateral GSV stripping and stab avulsions of varicose tributaries. Phlebographically confirmed incompetent perforating veins subfascially ligated in 20 participants by open long medial vertical approach. All 63 participants underwent SFV valve correction by internal valvuloplasty Control: unilateral GSV stripping and stab avulsions of varicose tributaries. Phlebographically confirmed incompetent perforating veins subfascially ligated in 21 participants by open long medial vertical approach No reference made to the use of low‐dose heparin and graduated compression stockings
Outcomes	No change in CEAP clinical class (defined as stable improvement) nor increase in clinical class (defined as aggravation), recurrent varicose veins RT and RVI were measured yearly by duplex scanning for 7 or 8 years postoperatively
Notes	Complications not mentioned Healing of 27 venous ulcers developing during 5 years prestudy; observation not mentioned separately 12 valvuloplasty failures (of 64) mainly during third year postoperatively of follow‐up Large quantity of data not suitable for analysis Study suggests possible benefit of valve repair at 7 years
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	No details given
Allocation concealment (selection bias)	High risk	No details given
Blinding of participants and personnel (performance bias) All outcomes	High risk	No details given
Blinding of outcome assessment (detection bias) All outcomes	High risk	No details given
Incomplete outcome data (attrition bias) All outcomes	Low risk	At the end of the fifth year, 19 participants withdrew from the study and were not included in the final data analysis
Selective reporting (reporting bias)	Low risk	All outcomes reported as planned
Other bias	Low risk	None