Journal of Thrombosis and Thrombolysis

, Volume 26, Issue 1, pp 14–21 | Cite as

Direct-to-patient expert system and home INR monitoring improves control of oral anticoagulation

  • Susan I. O’Shea
  • Murat O. Arcasoy
  • Gregory Samsa
  • Sandra E. Cummings
  • Elizabeth H. Thames
  • Richard S. Surwit
  • Thomas L. OrtelEmail author


Background and objective

Internet-based disease management programs have the potential to improve patient care. The objective of this study was to determine whether an interactive, internet-based system enabling supervised, patient self-management of oral anticoagulant therapy provided management comparable to an established anticoagulation clinic.


Sixty patients receiving chronic oral anticoagulant therapy who had access to the internet and a printer, were enrolled into this prospective, single-group, before-after study from a single clinic and managed between March 2002 and January 2003. Patients learned how to use a home prothrombin time monitor and how to access the system through the internet. Patients used the system for six months, with daily review by the supervising physician. The primary outcome variable was the difference in time in therapeutic range prior to and following introduction of internet-supervised patient self-management.


The mean time in therapeutic range increased from 63% in the anticoagulation clinic (control period) to 74.4% during internet-supervised patient self-management (study period). The mean difference score between control and study periods was 11.4% (P = 0.004, 95% confidence interval 5.5–17.3%). There were no hemorrhagic or thromboembolic complications.


This novel approach of internet-supervised patient self-management improved time in therapeutic range compared to an anticoagulation clinic. This is the first demonstration of an internet-based expert system enabling remote and effective management of patients on oral anticoagulants. Expert systems may be applicable for management of other chronic diseases.


Anticoagulation Expert system INR Patient self-management 



The authors wish to thank K. Vokaty, P. A.-C., and K. Baker, R. N., from the Duke Anticoagulation Management Service, for assistance with patient recruitment for the study, and M. Pound, for data entry. Funding for this study was provided by a Small Business and Innovative Research (SBIR) grant (R44 HL 66888) from the NIH to ZyCare®, Inc., Chapel Hill, NC. Home prothrombin time monitors were provided by International Technidyne Corporation, Edison, NJ. Dr. O’Shea was supported in part by a Clinical Scholar Award from the American Society of Hematology, and Dr. Ortel was supported in part by a Midcareer Investigator Award in Patient-Oriented Research (K24 AI0160301) from the NIH.


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Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Susan I. O’Shea
    • 1
    • 6
  • Murat O. Arcasoy
    • 1
  • Gregory Samsa
    • 2
  • Sandra E. Cummings
    • 3
  • Elizabeth H. Thames
    • 1
  • Richard S. Surwit
    • 3
    • 4
  • Thomas L. Ortel
    • 1
    • 5
    Email author
  1. 1.Division of Hematology, Department of MedicineDuke University Medical CenterDurhamUSA
  2. 2.Center for Clinical Health Policy ResearchDuke University Medical CenterDurhamUSA
  3. 3.ZyCare, IncChapel HillUSA
  4. 4.Department of Psychiatry and Behavioral SciencesDuke University Medical CenterDurhamUSA
  5. 5.Departments of Medicine & Pathology, Hemostasis and Thrombosis CenterDuke University Medical CenterDurhamUSA
  6. 6.Department of HaematologyCork University HospitalCorkIreland

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