Randomized Controlled Feasibility Trial of the Fearon Algorithm to Improve Management of Unstable Warfarin

All available historical data will be used to calculate with the Fearon algorithm the individual sensitivity to warfarin and to dose changes as well as lag time until a dose adjustment reaches full effect. Based on this a personal dosing nomogram will be developed and provided to the investigator and to the patients. This nomogram will be used during 6 month but override is possible if the investigator feels that the suggestion from the nomogram is unsafe.

Patients will receive warfarin dosing instructions from a trained nurse using fixed nomograms and computer-based dosing suggestion.