Oral anticoagulant therapy has changed little since the development of the coumarin drugs after the Second World War. The basic nature of the therapy, i.e. the balancing between thrombosis and... Show moreOral anticoagulant therapy has changed little since the development of the coumarin drugs after the Second World War. The basic nature of the therapy, i.e. the balancing between thrombosis and haemorrhage, makes it a therapy difficult to manage. Add to this the many influences from co-morbidity, co-medication, diet, metabolism, etc, and it becomes clear that there is little inherent stability to coumarin anti-vitamin K treatment. The studies included in this thesis were set up to look at different ways in which the quality of oral anticoagulant treatment can be improved. We looked at the percentage of time spent within the predefined INR target range with different coumarins (acenocoumarol and phenprocoumon), at patient self-management to further improve treatment quality in the setting of a highly structured system of anticoagulation clinics and the effects of this treatment modality on the quality of life of the patients. We also looked at the effects of chronic paracetamol intake on the INR, and at the relationship between the quality of oral anticoagulant therapy and recurrent thrombosis. Show less