The first ambulatory screening on thromboembolism : a multicentre, cross-sectional, observational study on risk factors for venous thromboembolism

Objectives: To assess the prevalence of risk factors for venous thromboembolism (VTE) and the prevalence of recent (< 1 year) VTE [including superficial vein thrombosis (SVT), deep vein thrombosis (DVT) and pulmonary embolism (PE)] amongst patients attending general practitioner (GP) surgeries. Design: Multicentre, cross-sectional, observational study. Setting: A total of 1536 GP surgeries. Participants: A total of 15 180 adult, co-operative subjects, who had consulted their GP for a health disorder and signed the informed consent form. Interventions: None. Main outcome measures: Prevalence of known VTE risk factors graded according to importance and prevalence of recent (< 1 year) VTE events (including SVT), based on interviews. Results: About 1:5 patients had at least one strong risk factor and about 1:20 had at least two risk factors, with no difference between sexes. The prevalence of strong risk factors increased with age. Most were related to medical conditions: history of SVT and/or DVT/PE, heart failure and malignancy. About 3:4 women and 2:3 men had at least one moderate to weak risk factor; nearly 1:2 women and 1:3 men had at least two moderate to weak risk factors. The most common were: history of VTE, smoking, history of miscarriage, estrogen therapy, obesity, and varicose veins. Overall, 80% women and 67% men had at least one risk factor, and 50% women and 35% men had at least two risk factors. The prevalence of recent (< 1 year) VTE was 3.4% in women and 2.4% in men, and increased with age. The majority of cases were SVT in both sexes (2.5% in women and 1.5% in men). Conclusions: The prevalence of risk factors for VTE amongst patients attending GP surgeries is high. GPs should bear this in mind during their daily practice.