Self-monitoring for patients on warfarin?

One estimate suggests that at least 1 million people in the UK are on the anticoagulant warfarin.1 This number could increase as more people are treated with the drug for atrial fibrillation and as the elderly population increases.1 Careful control of anticoagulation is essential with warfarin therapy and, traditionally, patients on the drug have had to travel to a clinic to have their blood coagulation time tested. However, the availability of portable self-testing machines makes it possible for some patients to monitor their blood coagulation time at home. Here we examine the evidence on the efficacy and safety of such self-monitoring and consider which patients it most suits and whether more widespread use of the approach is justified.