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.
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 self-management; 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.
Only 25.6% of invited patients agreed to participate 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.
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.