The aim of this study is to perform a randomized trial comparing the use of the algorithm, with dosing of warfarin in standard manual dosage clinical practice, in a high quality anticoagulant setting (PSM). This is done for safety concerns and to ensure good performance of the algorithm when used in a clinical setup. The results from the study are expected to increase our knowledge of efficacy by using the algorithm in clinical practice.

Inclusion Criteria

• Participants will be those ≥18 years old, must refer to Trombosecenter Aalborg and have to be educated as PSM patient
• Have to be treated for at least 1 month and willing to sign informed consent

Exclusion Criteria

• OAT treatment with phenprocoumon
• Lack of ability to handle the interface on the software used in the study (evaluated by the investigator present at the information meeting)
• Pregnancy
• Those with severe co-morbidities (e.g., creatinine > 2.5, hepatic insufficiency, active malignancy, advanced physiological age, noncompliance risk, expected survival <6 months), and physician or patient preference.