METHOD: This will be a three year quasi- experimental prospective study with a control group. 333 patients on anticoagulant therapy from five health centres of the Basque Health Service are to be followed up for a period of six months each after the intervention, to assess their ability to self-test and self-manage. The intervention will consist of a patient training programme involving the provision of information and practical training concerning their condition and its treatment, as well as how to use a portable blood coagulation monitoring device and adjust their anticoagulant dose.