Devices are available that enable patients who take warfarin to measure their INR values at home. Patients with such devices can adjust their warfarin doses as needed after phone consultations with their clinicians (self-monitoring) or according to predetermined algorithms (self-management). Generally, randomized controlled trials in which self-monitoring or self-management was compared with traditional clinician management of oral anticoagulation have shown no significant differences in clinical outcomes.
In a meta-analysis, researchers pooled data from 14 such trials (total, 3049 patients). Taken together, the data showed that thromboembolic events were reduced significantly by self-monitoring (by 43%) or self-management (by 73%). Major hemorrhage was reduced significantly by self-monitoring (by 44%), but not by self-management. All-cause mortality rates were significantly lower with self-management (by 63%), but not with self-monitoring, than with clinical management. When all data for self-monitoring and self-management were pooled, patients who obtained their INR values at home suffered significantly fewer thromboembolic events (by 55%), major hemorrhages (by 35%), and all-cause deaths (by 39%).
These data strongly suggest that, compared with traditional management, home INR monitoring significantly lowers overall mortality rates and adverse events due to under- and over-anticoagulation. Not all patients are candidates for home INR monitoring; the safety and effectiveness of this approach will depend on appropriate patient selection and adequate training.
Reference:
Heneghan C et al. Self-monitoring of oral anticoagulation: A systematic review and meta-analysis. Lancet 2006 Feb 4; 367:404-11.