Self‐management of oral anticoagulation: long‐term results

Dear Sir, The increasing number of indications for oral anticoagulation has raised concerns how this therapy should be undertaken. In addition, control of oral anticoagulation therapy has been reported to be often inadequate. Prospective randomized controlled investigations suggest that patients’ self-management of oral anticoagulation may lead to improved control. Prospective long-term studies of this intervention are not available. Therefore, we have assessed during a period of 5 years the effects of patients’ self-management of oral anticoagulation on long-term compliance with this kind of therapy, accuracy of control, measures of treatment-related quality of life and bleeding and thromboembolic complications. A structured teaching and treatment programme for self-management of oral anticoagulation was offered to 178 patients. Follow-up was until death or for a period of 5 years resulting in 809 patient years (py). In the initial randomized controlled part of this study [1] we have shown that self-management of oral anticoagulation can be reliably performed by patients and improves quality of anticoagulation control and treatment-related quality of life. In the second part of this study, we have demonstrated patients’ compliance to this form of therapy in the long-term and we have shown that it is associated with an improvement of the quality of anticoagulation control, which is maintained during the follow-up of 5 years. Before participation in the self-management programme the squared international normalized ratio (INR) deviation in the intervention group was 1.32 and only 29% of INR measurements were within the target range. At the end of the randomized controlled part of this study, the squared INR deviation from the mean of the target range in the intervention group was 0.65 with 53% of INR values being within the target range. After 5 years the squared INR deviation was even lower at 0.44 and the percentage of INR values within target range increased to 62%. Hence, not only the improvement in the quality of anticoagulation control after participation in the self-management programme is long lasting, but it may even improve further with the duration of patients’ self-management. Our prospective study confirms and extends previous controlled study results [2–4] indicating that this form of anticoagulation treatment improves both quality of care and quality of life and supports patients’ demand for a broader access to this form of treatment. As in this study the control-group patients have also participated in the self-management programme after 6 months, it is not possible to evaluate the risk of complications in a randomized controlled way. However, when compared with the previously published risk evaluations in this prospective study self-management of oral anticoagulation was associated with a relatively low risk of major bleeding (0.62 per 100 py), while the risk of thromboembolic complications (1.1 per 100 py) was comparable with results in an anticoagulation clinic. From the 150 patients available for the final 5-year examination, 134 (89%) performed self-monitoring and 116 (77%) self-adaptation of cumarin dosage. At baseline 32% of patients were within the INR target range; during the final year of the follow-up period 62% of INR self-measurements were within the target range. On self-monitoring, the mean time within the target range was 225 days per year (d/y) and 80 d/y below and 60 d/y above the target range. During the follow-up period, five major bleeding complications (0.62 per 100 py) and nine thromboembolic events (1.1 per 100 py) occurred. When compared with baseline, parameters of quality of life improved (Table 1). We conclude from these results that after participation in a structured teaching and treatment programme, compliance with self-management of oral anticoagulation persists in the long-term, results in an improvement of accuracy of anticoagulation control and quality of life and is associated with a relatively low risk of bleeding and thromboembolism. DIeM – Institute for Evidence Based Medicine, Cologne, Germany has received scientific grants from Roche Diagnostics, Mannheim, Germany for development and evaluation of structured programmes for self-management of oral anticoagulation.