Research Abstracts

The Journal of Informed Pharmacotherapy 2000;2:400.

Suitability of Warfarin Self-Management in a Random Population

Poonam Sethi, B.Sc.(Pharm), Rubina Sunderji, B.Sc.(Pharm), Pharm.D., FCSHP, Karen Shalansky, Pharm.D., FCSHP, Kenneth Gin, M.D., FRCPC, Anthony Fung, M.B., FRCPC

Clinical Service Unit Pharmaceutical Sciences and Clinical Practice Unit Cardiac Sciences, Vancouver Hospital and Health Sciences Centre and Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada

University of British Columbia Pharmacy 405 (Directed Studies) Research Presentation Seminar (Podium presentation). Vancouver, British Columbia, Canada. April 7, 2000. (Unfunded study).


Patient self-management of oral anticoagulation using a home INR monitor has been shown to provide superior anticoagulation control compared to traditional physician-managed therapy. Patients in these studies are carefully selected, therefore there is little information about the applicability of this strategy to the general population.


To determine the feasibility of anticoagulation self-management in a group of cardiac patients in a cardiothoracic surgery step-down unit.


A cardiothoracic surgery step-down patient unit in a 1000-bed Canadian tertiary teaching hospital.


This was a two-phase study conducted over a four-month period.  Phase I: Consecutive inpatients prescribed warfarin were randomly assessed on post-operative day 4-5 for eligibility of self-management.  Using a questionnaire format, patients were evaluated for fluency in English, medication compliance, interest in self-management, willingness to document INR results and warfarin doses administered, manual dexterity and comfort with finger pricking. Phase II: All patients were contacted at home 4 weeks after the initial in hospital contact to confirm eligibility for self-management.

Main Outcome Measures

The primary outcome measure was the proportion of patients suitable for warfarin self-management at post-operative day 4-5 and at home 4 weeks later.  Secondary outcome measures were patient characteristics that appear to influence patient suitability.


Forty-two patients were evaluated during the period November 1999 to March 2000.  The majority of patients (81%) were receiving warfarin for a mechanical heart valve.  Twenty-six patients (62%) were deemed suitable for self-management during Phase I, while 25 (60%) were considered suitable during Phase II.  Of the 17 patients who were deemed ineligible at final contact, the reasons included a preference for physician-management (9), reluctance with finger pricking (3) or documentation of results (1), lack of english comprehension (2) and mental incompetence (2).  Preliminary evaluation suggests that older age (68 yrs vs. 58 yrs), female gender and prior warfarin use negatively effect patient suitability.


Based upon the preliminary results of this study, it appears that a substantial proportion of cardiac patients are potential candidates for self-management of their anticoagulation.

Copyright © 2000 by the Journal of Informed Pharmacotherapy. All rights reserved.