In this thesis we show the results of the AT-AGE study, a two-center, population based case-control study in Leiden, the Netherlands and Burlington, Vermont, US, in which consecutive patients aged... Show moreIn this thesis we show the results of the AT-AGE study, a two-center, population based case-control study in Leiden, the Netherlands and Burlington, Vermont, US, in which consecutive patients aged 70 years and older with deep venous thrombosis (DVT) in the leg or a pulmonary embolism (PE), were identified. The AT-AGE study was specifically designed to optimise the participation-rate in the older population. Therefore, we performed home visits to all participants. We showed that conventional risk factors such as immobilisation due to hospital admission, and also immobility at home, due to for instance infection and minor injury, increase the risk of venous thrombosis. Also genetic risk factors, such as Factor V Leiden (FVL, rs6025) and the prothrombin 20210A mutation (PT20210, rs1799963) increase the risk of venous thrombosis. We report the presence of age-specific risk factors: functional impairment, low hand grip strength and venous insufficiency, such as varicose veins and leg oedema. Also we identified new high risk groups in older people, e.g., recent hospital discharge in which preventive measures could be of special interest. Show less