LONG-TERM PATIENT SELF-MANAGEMENT OF ORAL ANTICOAGULATION

Background: The management of oral anticoagulation is fraught with dif ficulties. This study assessed a new model of anticoagulation manageme nt regarding the ability, safety, and efficacy of patients to self-mon itor and self-adjust the dose of their oral anticoagulants guided by a capillary whole-blood prothrombin time (PT) monitor. Methods: This in vestigation is a retrospective cohort study of 20 patients compared wi th 20 matched control patients receiving oral anticoagulation at a ter tiary medical institution. Results: Study patients monitored their PTs 2153 times during a mean interval of 44.7 months compared with 1608 P Ts in matched control patients during a mean interval of 42.5 months. Study patients made an average of 11.5 dosage changes per patient, con trasted with 22.7 changes per control patient (P<.001). The PTs in stu dy patients were within the recommended therapeutic range in 88.6% (95 % confidence interval, 87.2 to 89.9) of the determinations compared wi th 68.0% (95% confidence interval, 65.7 to 70.3, P<.001) of the determ inations made by the matched control patients. In response to the 2153 PTs, study patients made 67 (3.1%) dosage decisions that were conside red incorrect based on physician guidelines. None of these changes led to adverse outcomes. There was no significant difference in complicat ion rates between the two groups. Conclusions: Results from what is th e first long-term study of patient self-monitoring of PTs and self-adj ustment of the warfarin sodium dosage for oral anticoagulation suggest that patients can successfully measure their own PTs, adjust their ow n warfarin dosage, and achieve a degree of therapeutic effectiveness a t least as good, if not better than patients managed in an anti- coagu lation clinic. Larger, prospective, randomized trials are needed to co nfirm the efficacy and safety of this new approach to therapy and to a ssess its cost-effectiveness.