Prospective analysis of risk factors and distribution of venous thromboembolism in the population-based Malmö Thrombophilia Study (MATS)

Background

Despite venous thromboembolism (VTE) being a major cause of morbidity and mortality, there is still limited information on its prevalence and incidence in the general population.

Objective

To evaluate risk factors, distribution and epidemiology of VTE in the Malmö area with 280 000 inhabitants.

Methods

Patients diagnosed with VTE at Malmö University Hospital in 1998–2006 were invited to a prospective population-based study. Blood sampling and a questionnaire study could be performed in 70% of patients. Remaining 30% were excluded due to language problems, dementia, other severe disease, or unwillingness to participate.

Results

During 1998–2006 1140 VTE patients (559 men [49%, age 62 ± 16 years] and 581 women [51%, age 61 ± 20 years]) were included. Deep venous thrombosis (DVT) occurred in 882 (77%), pulmonary embolism (PE) in 330 (29%), and both DVT and PE in 72 (6%). The most common acquired risk factors among VTE patients were hormone therapy (24% of female DVT patients and 19% of female PE patients), immobilisation (17% of DVT patients and 18% of PE patients), previous surgery (13% of DVT patients and 19% of PE patients), and concomitant malignant disease (12% of DVT patients and 11% of PE patients). A positive family history for VTE was obtained from 25% of DVT patients and 22% of PE patients.Yearly incidences of VTE, DVT and PE in Malmö were 66, 51, and 19/100.000, respectively.

Conclusion

Hormone therapy, immobilisation, previous surgery and concomitant malignancy were the most common acquired risk factors among VTE patients in this population-based study. The VTE-incidence was lower than in earlier epidemiological studies.