Incidence and Risk Factors for Venous Reflux in the General Population: Edinburgh Vein Study

Abstract

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. 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. 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. 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.