Correspondence Department of Medicine, Boston University School of Medicine, 88 E Newton St, Boston, MA 02118, USA.

Email jack.ansell@bmc.org

Original article

Menéndez Jándula B et al. (2005) Comparing self-management of oral anticoagulant therapy with clinical management: a randomized trial. Ann Intern Med 142: 1–10   PubMed

Synopsis

Background

Portable coagulometers have enabled patients to test their own international normalized ratio (INR) and therefore manage their own anticoagulation therapy, independent from their physician. In this paper, Menéndez-Jándula et al. investigate whether self-managed anticoagulation therapy is an efficient and feasible option.

Objective

To determine whether oral anticoagulation therapy managed by the patient and anticoagulation therapy managed by a clinic provide the same safety and quality of control.

Design and intervention

Between January 2001 and July 2002, this trial randomly preselected patients from a database of patients already receiving clinically managed anticoagulant therapy. Patients who were over 18 years old and had received anticoagulant therapy for 3 months or more were included. Eligible patients were interviewed and consenting patients were randomly assigned to self-managed or clinic-managed anticoagulation. All patients randomized to the self-management group underwent at least 4 h training to teach them how to use a coagulometer, interpret their INR and adjust their anticoagulant dose accordingly. Patients only entered the study when their self-management was considered competent. Self-managed patients performed an INR test once a week using the CoaguChek S portable coagulometer (Roche Diagnostics, Mannheim, Germany). Patients in the clinically managed group had INR tests every 4 weeks using a KC10 coagulometer (Amelung, Lemgo, Germany). All patients were followed up by telephone interview each month. Outcomes were diagnosed by an independent masked physician. All analyses were done by intention to treat.

Outcome measures

The study measured the percentage of INR values within the target range of 2.5–3.5. Major events included thromboembolic complications, bleeding requiring hospital admission or blood transfusion, and life-threatening bleeding.

Results

The original database included 5,000 patients. After random preselection, 737 eligible patients gave their consent and joined the study. Of these, 368 patients were assigned to self-managed anticoagulation and 369 were assigned clinic-managed anticoagulation. Due to patient withdrawal, lack of confidence and inability to manage self-monitoring, only 300 self-managed patients entered the study. When analyzed by intention to treat, a greater percentage of self-managed patients had INR values within the target range compared with clinic-managed patients (58.6% vs 55.6%, 95% CI 0.4–5.4, P = 0.02). There were fewer anticoagulation-related major events in the self-managed group than the clinic-managed group (8 vs 27, unadjusted risk difference 5.1%, 95% CI 1.7–8.5) and fewer self-managed patients died compared with the clinic-managed patients (6 vs 15, unadjusted risk difference 2.5%, 95% CI 0.0–5.1).

Conclusion

Conventional clinic-managed anticoagulation therapy and self-managed oral anticoagulation therapy offer a similar quality of INR control. Furthermore, self-managed anticoagulation reduced the number of deaths and major events but Menéndez-Jándula et al. point out that not all patients will be suited to managing their own INR levels.

Commentary

Oral anticoagulants are one of the most common causes of drug-induced adverse events. Expert dose management—keeping the patient within a narrow therapeutic INR range—is required to avoid adverse events. Because of the intensity of dose management required, anticoagulation clinics have been developed to help physicians.¹ Focused management by anticoagulation clinics has been shown to improve patients' outcomes when compared with routine management provided by physicians,^{1, 2} but estimates suggest that less than 50% of patients in the US who receive oral anticoagulants are managed by such clinics. 'Point of care' prothrombin-time monitoring technology, developed 20 years ago, introduced a new model of care by enabling patients to self-test through fingerstick INR monitoring. Using this method, patients can either monitor their own INR at home and receive dose-adjustment guidelines from their physician, or after proper training, adjust their own anticoagulation dose.¹ Evidence suggests that patients receiving this type of care achieve significantly better outcomes than patients receiving routine care by individual physicians, but only slightly better outcomes than focused care delivered by an anticoagulation clinic.^{2, 3}

In this study, Menéndez-Jándula et al. have provided additional evidence for the benefits of patient self-management, compared with the equivalent anticoagulation-clinic care. In this randomized, unblinded trial, 300 patients managed their own therapy after training. Patients' outcomes over the next 12 months were compared with the outcomes of 369 patients managed by an anticoagulation clinic. The primary outcome was either the percentage of INRs or time in the therapeutic range. The frequency of major hemorrhage or thromboembolism was a secondary outcome. The self-managed group had significantly more INRs in the target therapeutic range (58.6% vs 55.6%), a surrogate measure of improved outcome,⁴ but the calculated time in range was not different between the two groups. In both cases, this rate is considerably below the levels of approximately 70–80% within INR range achieved in previous trials.² The self-managed patients experienced significantly fewer major adverse events than the anticoagulation clinic group (2.2% vs 7.3%, respectively), the difference being primarily attributable to fewer thromboembolic events. This study was limited, however, as all patients were managed at one center, and there was a high dropout rate from the interventional self-managed group, which suggests that this type of care is not suitable for all patients who need anticoagulation therapy.

What impact should these results have on anticoagulation therapy in general? Menéndez-Jándula and colleagues' study, with its large patient base, mirrors a number of other studies of self-managed oral anticoagulation therapy and further supports this method of therapy. Compared with its use in other countries,⁵ however, patient self-management has not taken hold in the US. A major barrier is that reimbursement is limited to patients with mechanical heart valves only, and there is currently a complicated reimbursement scheme for the implementation of self-managed anticoagulation. Concerns about instrument accuracy and physicians being liable for adverse events, and possibly a low level of awareness that such therapy is available, limit the use of this strategy. A large, prospective, randomized trial conducted by the Veterans Administration health centers will conclude in approximately 2 years, and if the results are similarly positive, should provide further support for this model of therapy.

Acknowledgments

The synopsis was written by Hannah Camm, Associate Editor, Nature Clinical Practice.

References

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Subject areas under which this article appears: Therapy