October 21st, 2010
INR Home Testing Found Comparable to Point-of-Care Testing
Larry Husten, PHD
Weekly INR self-testing at home is comparable to monthly point-of-care testing, according to results of THINRS (the Home International Normalized Ratio Study), published in the New England Journal of Medicine. David Matchar and colleagues found no difference in the incidence of stroke, major bleeding episode, or death in the 2922 patients taking warfarin who were randomized to one of the two methods and followed for 2 to 4.75 years. Compared with the point-of-care testing group, the self-testing group reported more minor bleeds but had a small but statistically significant improvement in the percentage of time within the target INR range as well as greater satisfaction with anticoagulation therapy.
The results allow the authors to rule out with “a high degree of confidence” both a large negative effect and positive effect of home self-testing. They conclude: “In light of the poor record of usual care and the value of anticoagulation in preventing major events, we recommend that self-testing be considered for patients whose access to high-quality anticoagulation care is limited by disability, geographic distance, or other factors, if the alternative would be to withhold a highly effective treatment.”