title: Paper-based dosing algorithms for maintenance of warfarin anticoagulation.
abstract: We examined the quality of anticoagulation produced by two paper-based warfarin dosing algorithms in a randomized clinical trial of warfarin therapy. Fifty-eight patients were randomized to receive warfarin at a target international normalized ratio (INR) range of 2.1-3.0 and were followed for an average of 2.7 years. As a proportion of total patient-time, the percentage of time spent above, within, and below the therapeutic range was 11%, 71%, and 19% respectively. Fifty-six patients were randomized to receive warfarin at a higher target INR range (3.1-4.0) and had INRs within the therapeutic range for 40% of total patient time. We conclude that the performance, minimal cost, and ease-of-use of these algorithms make them well-suited for patient management within primary-care and research settings.
authors.affiliation: PGY1, Internal Medicine, University of Toronto, Toronto, ON, Canada, M5R 2N9. sarah.wilson@utoronto.ca
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Wilson
authors.forename: Lorrie
authors.initials: L
authors.lastname: Costantini
authors.forename: Mark A
authors.initials: MA
authors.lastname: Crowther
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000925:Anticoagulants / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D014859:Warfarin / Q000008:administration & dosage*
chemical_list: D000925:Anticoagulants; D014859:Warfarin