Sunderji R et al. (2004) A randomized trial of patient self-managed versus physician-managed oral anticoagulation. Can J Cardiol 20: 1117–1123

Patients receiving warfarin require regular monitoring of the international normalized ratio (INR) and appropriate dosage adjustments in order to remain within the drug's narrow therapeutic range. Although anticoagulation clinics are available in some countries, warfarin management is usually conducted by the primary care physician. Self-management (SM) of warfarin by the patient may be a superior strategy, in terms of both convenience and anticoagulation control. Sunderji and colleagues have explored this in a recent Canadian study.

The 8-month trial randomized patients to their usual physician-management (PM) or to SM (n = 70 in each group). Following training, those in the SM group began testing their INR with a point-of-care monitor, which calculates the INR using blood from fingertip puncture. The patients then adjusted their warfarin doses using a nomogram.

Thirteen patients dropped out of the SM group as they were unable to self-manage. Based on an intention-to-treat analysis, patients in the SM group maintained their INR values within the target range 71.8% of the time, compared with 63.2% in the PM group. This difference did not reach statistical significance. The proportion of time spent below the therapeutic range, however, was significantly lower in self-managed patients (15.0% vs 27.3%, P = 0.04). All patients completing SM preferred to continue managing their own therapy.

The authors conclude that SM was feasible and appeared safe in these patients, although maintenance of therapeutic anticoagulation was not improved. Cost of training and point-of-care monitors may be a barrier to self-management strategies.