title: Incidence and risk factors for venous reflux in the general population: Edinburgh Vein Study.
abstract: OBJECTIVE
  Chronic venous disease (CVD) is common, but the incidence of venous reflux, a precursor to this condition, is unknown. This study measured the incidence of venous reflux and associated risk factors, and examined the association between venous reflux and the incidence of CVD.
  
  
  METHODS
  In the Edinburgh Vein Study, a random sample of 1566 men and women aged 18-64 years were examined at baseline. Eight hundred and eighty of these patients were followed up 13 years and underwent an examination comprising clinical classification of CVD and duplex scanning of the deep and superficial systems to measure venous reflux ≥0.5 s.
  
  
  RESULTS
  The 13-year incidence of reflux was 12.7% (95% confidence interval [CI] 9.2-17.2), equivalent to an annual incidence of 0.9% (95% CI 0.7-1.3). The 13-year incidence of isolated superficial, isolated deep, and combined deep and superficial reflux was 8.8% (95% CI 5.6-12.0), 2.6% (95% CI 1.2-5.0), and 1.3% (95% CI 0.4-3.2), respectively. The highest incidence was in the great saphenous vein in the lower thigh (8.1%, 95% CI 5.4-11.8). There were no age or sex differences (p > .050). The risk of developing reflux was associated with being overweight (odds ratio [OR] 2.1, 95% CI 1.0-4.4) and with history of deep vein thrombosis (OR 11.3, 95% CI 1.0-132.3). Venous reflux at baseline was associated with new varicose veins at follow up (p < .001): the age- and sex-adjusted OR was 4.4 (95% CI 1.8-10.8) in those with isolated superficial reflux and 7.3 (95% CI 2.6-22.5) in those with combined deep and superficial reflux.
  
  
  CONCLUSIONS
  For every year of follow-up, around 1% of this adult population developed venous reflux. In two thirds of cases, the superficial system was affected. Venous reflux increased the risk of developing varicose veins, especially when combined deep and superficial reflux was present.
authors.affiliation: Centre for Population Health Sciences, Medical School, Teviot Place, University of Edinburgh, Edinburgh EH8 9AG, UK. Electronic address: lindsay.robertson@ed.ac.uk.
authors.forename: L A
authors.initials: LA
authors.lastname: Robertson
authors.affiliation: Centre for Population Health Sciences, Medical School, Teviot Place, University of Edinburgh, Edinburgh EH8 9AG, UK.
authors.forename: C J
authors.initials: CJ
authors.lastname: Evans
authors.affiliation: Division of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Lee
authors.affiliation: Radiology Department, Royal Infirmary of Edinburgh, Edinburgh, UK.
authors.forename: P L
authors.initials: PL
authors.lastname: Allan
authors.affiliation: University of Edinburgh, Edinburgh, UK.
authors.forename: C V
authors.initials: CV
authors.lastname: Ruckley
authors.affiliation: Centre for Population Health Sciences, Medical School, Teviot Place, University of Edinburgh, Edinburgh EH8 9AG, UK.
authors.forename: F G R
authors.initials: FG
authors.lastname: Fowkes
mesh_terms: D000293:Adolescent; D000328:Adult; D016009:Chi-Square Distribution; D002908:Chronic Disease; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D012606:Scotland / Q000453:epidemiology; D013997:Time Factors; D018616:Ultrasonography, Doppler, Duplex; D014648:Varicose Veins / Q000453:epidemiology; D014689:Venous Insufficiency / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000503:physiopathology; D020246:Venous Thrombosis; D055815:Young Adult
keywords: Cohort; Incidence; Risk factors; Venous reflux