Feasibility of Warfarin Anticoagulation Management with a Patient Self-Testing Model in Korea

Purpose: Dose adjustments of warfarin are mandatory for effective and safe treatment due to the narrow therapeutic window.Until now, no domestic data have been reported on warfarin anticoagulation management using a patient self-testing (PST) model.Here, we describe our experiences with warfarin management with a PST model.Methods: Data were collected retrospectively from 13 patients who had been anti-coagulated with warfarin from Jan 1, 2010 to May 30, 2011.Time in therapeutic international normalized ratio (INR) range (TTR) and thromboembolic or bleeding complications were considered as the primary and secondary outcomes, respectively.The INR values obtained by point-of-care (POC) self-testing at home were sent to the anticoagulation clinic by telephone and the patients were informed of their warfarin dosage changes and next scheduled INR testing date by the anticoagulation clinical staff.Warfarin dose-adjustment and INR determination were performed according to the recommendations of the warfarin dosage-adjustment algorithm introduced in the previous study. Results:The average interval of POC INR monitoring per patient was 14.2 ± 5.1 days.Our results showed that well-trained patients could obtain their INRs by self-testing, and the mean TTR was 67.0%.During the follow-up period, neither recurrent venous thromboembolism nor bleeding complications were noted.There was one case of mortality due to the progression of gastric cancer that was diagnosed during warfarin treatment.Conclusion: The present study is the first to report on warfarin management using the PST model in Korea.PST model is considered to be a promising tool for maintaining adequate TTR.