Risk factors for chronic venous insufficiency: a dual case-control study.J Vasc Surg 1995; 22(5):622-8JV
Most epidemiologic studies on chronic venous insufficiency (CVI) are cross-sectional surveys that suggest potential risk factors by describing their population. However, these relationships could be due to the CVI population's older age. We performed a dual case-control study with multivariate analysis to address this issue.
Ninety-three patients with venous ulcers, 129 patients with varicose veins (VV), and 113 general population control patients from two hospitals were interviewed by use of a standardized questionnaire covering medical history, patient demographics, medications, and lifestyle questions. Univariate and multivariate analyses were used to compare the groups.
Univariate analyses showed CVI to be characterized by several factors, many of which were found to be age related after multivariate analysis. Age-adjusted relationships for CVI include male sex and obesity. Histories of serious leg injury or phlebitis were important associations resulting in a 2.4-fold and 25.7-fold increase in risk for CVI, respectively. After adjusting for age, subjects with VV tend to be younger and female, to more frequently have a history of phlebitis, and to report a family history of VV more frequently than control subjects.
Many of the previously suggested associations found with CVI are in reality due to this population's greater age. Patients with CVI are older, male, obese, have a history of phlebitis, and have a history of serious leg injury. These results suggest that a prior deep vein thrombosis, either clinical or subclinical, may be a predisposing factor for CVI.