Comparison of the Quality of Oral Anticoagulant Therapy Through Patient Self-management and Management by Specialized Anticoagulation Clinics in the Netherlands

Background: Several studies have demonstrated that patient self-management of oral anticoagulant therapy (OAT) can improve treatment quality.However, most of these studies were not conducted within a specialized anticoagulation care system.The objective of the present study was to determine whether patient self-management of OAT improves the quality of care delivered by anticoagulation clinics.Methods: In this randomized study by 2 Dutch anticoagulation clinics 341 patients aged between 18 and 75 years and receiving long-term OAT were divided into 4 groups: an existing routine care group of patients untrained in selfmanagement; a routine care group of trained patients; a group managed weekly at an anticoagulation clinic where international normalized ratios were measured by trained patients; and weekly patient self-management.A 2-step randomization procedure was followed: first, a Zelen-design randomization was performed to distribute patients (without informing them) to the existing care group or to receive training in self-management; second, trained patients were randomized to the 3 other study groups.Results: Only 25.6% of invited patients agreed to par-ticipate in the training program.Patients who remained in the existing care group were within the international normalized ratio target range 63.5% of the time.The type of coumarin taken was a major predicting factor of OAT quality.In all study groups phenprocoumon outperformed acenocoumarol by 11.6% (95% confidence interval [CI] , 6.6%-16.5%).Weekly management with phenprocoumon led to a 6.5% improvement (95% CI , 0.0%-13.1%) in time in the international normalized ratio target range when patients were managed at an anticoagulation clinic and to an 8.7% improvement (95% CI , 1.6%-15.9%)when patients were self-managed.Weekly management with acenocoumarol did not improve the quality of OAT. Conclusion:With selected patients, the quality of OAT obtained through patient self-management is at least as high as that delivered by specialized physicians at anticoagulation clinics.Weekly management of OAT with long-acting phenprocoumon has to be preferred at anticoagulation clinics or, where possible, through patient self-management.