Veneuze en arteri_le trombose zijn twee van de belangrijkste oorzaken van ziekte en sterfte in Westerse landen. Hoewel de laatste jaren is er veel bekend geworden over de oorzaken die de kans op... Show moreVeneuze en arteri_le trombose zijn twee van de belangrijkste oorzaken van ziekte en sterfte in Westerse landen. Hoewel de laatste jaren is er veel bekend geworden over de oorzaken die de kans op het krijgen van trombose verhogen, zijn er nog veel onduidelijkheden. In dit proefschrift hebben we getracht om naar aanleiding van eerder uitgevoerde genetische en observationele studies nieuwe risicofactoren voor deze twee soorten trombose op te zoeken. Tevens is de samenhang tussen arteri_le en veneuze trombose en de preventie voor trombose tijdens zwangerschap besproken. Show less
In venous thrombosis, a blood clot develops in a vein, usually a deep vein of the leg, causing obstruction of the blood flow. Venous thrombosis is a multicausal disease, in which genes and... Show moreIn venous thrombosis, a blood clot develops in a vein, usually a deep vein of the leg, causing obstruction of the blood flow. Venous thrombosis is a multicausal disease, in which genes and environment interact. One of the environmental factors that increases the risk of venous thrombosis is long distance travel. This thesis describes the results of several studies on epidemiological aspects of the association between long distance travel and venous thrombosis. In a study among frequently traveling employees of international organizations, the absolute risk of venous thrombosis after long distance flights, the effect of duration of travel, time after travel and exposure to several flights at the same time and the effect of interaction with other risk factors for venous thrombosis was assessed. In a population-based case-control study, the effect of elevated levels of coagulation factors in long distance travelers was evaluated. Finally, the occurrence of venous thrombosis among commercial airline pilots was studied. The main conclusion is that the risk of venous thrombosis in healthy travellers is not high enough to promote widespread use of aggressive prophylaxis, such as anticoagulant therapy. However, in some travellers at increased risk, the risk-benefit ratio may favour the use of prophylactic measures. Show less
The studies described in this thesis had two main aims: 1) To study the quality of life of patients with venous thrombosis and to examine the role of illness perceptions in explaining the quality... Show moreThe studies described in this thesis had two main aims: 1) To study the quality of life of patients with venous thrombosis and to examine the role of illness perceptions in explaining the quality of life of these patients. 2) To assess the psychological consequences of genetic testing for thrombophilia, using the Common-Sense Model (Leventhal et al.., 1984) as a theoretical framework.The studies performed to assess aim 1 form the first part of the thesis and show that the effect of venous thrombosis on quality of life should not be underestimated, even some years after the venous thrombosis. Furthermore, results give an indication that besides the presence of the postthrombotic syndrome, illness perceptions may help to explain quality of life in patients with venous thrombosis.In the second part of the thesis aim 2 is addressed. Genetic testing for thrombophilia does not have many adverse psychological consequences. However, certain vulnerable individuals may still experience considerable worry about getting venous thrombosis. Furthermore, results indicate that the Common-Sense Model can act as a useful framework to enhance understanding of how factors contribute to influence psychological response to risk of disease. Show less
Venous thrombosis is a well-known complication of central vein catheters (CVCs), which may cause serious morbidity and may result in potentially lethal complications such as pulmonary embolism. In... Show moreVenous thrombosis is a well-known complication of central vein catheters (CVCs), which may cause serious morbidity and may result in potentially lethal complications such as pulmonary embolism. In this thesis the general risk of CVC related thrombosis has been assessed, i.e., what is the overall risk of developing CVC related thrombosis? Which patients are prone to develop thrombosis with its associated morbidity? Are we able to predict this risk by routine surveillance in "high-risk" patients? Better knowledge of the incidence of CVC related thrombosis and identification of high-risk groups will assist clinicians in decision making about CVC use in the various patient-groups and in whom anticoagulant prophylaxis may be warranted. In summary, the a priori determination of common inherited and acquired risk factors may form a basis to guide (prophylactic) treatment decisions. Vulnerable patients may benefit the most, i.e. those who have a high risk of clinically manifest thrombosis, and who are at risk of hemorrhage, such as patients who undergo intensive chemotherapy. Besides, surveillance of these patients with screening by ultrasound, or alternatively surveillances cultures, may be useful to identify patients at high or low risk for clinically manifest CVC related thrombosis, and focused early intervention may be initiated. Show less
