POC PT/INR testing: a better choice for patients and providers

Nov. 1, 2009

Oral anticoagulant therapy with warfarin is generally used
for the prevention and treatment of strokes related to atrial fibrillation;
deep venous thrombosis, or DVT; and other vascular conditions. Under many
conditions, the therapy can be highly effective.1,2 Sometimes,
the management of that therapy can be highly ineffective. One
of the key reasons is inefficient office-workflow models that make it hard
to manage warfarin patients cost effectively.3,4,5 There is a
solution, however — one that can benefit not only patients but also medical
labs, clinics, and physician practices as well.

Systematic focus on patient care

Systematic anticoagulation management (SAM) is a
patient-focused approach, based at the point of care rather than an outside
(or central) lab.6,7 It shifts the focus in warfarin therapy from
a very labor-intensive administrative process to personalized patient care.
The model includes four components, which clinicians can adapt to meet their

  • direct, active patient management, in which a single
    qualified medical professional has primary responsibility for managing
    all patient care;
  • patient scheduling and tracking;
  • accessible, accurate, and frequent PT/INR testing;
  • patient-specific care.

Multiple studies have shown that a systematic approach to
anticoagulation management, focused at the point of care, may increase the
time patients are in range and reduce the risk of adverse events.4,8,9

In particular, these studies have shown that
point-of-care PT/INR testing and anticoagulation management can be more cost
effective than traditional medical care. By putting patient, physician, and
test results in the same place at the same time, prompt and proper patient
evaluation and education can be facilitated.2,3

Immediate access to results

Point-of-care PT/INR monitoring combines testing accuracy
comparable to that of reference laboratories with the convenience of
immediate access to test results.10,11 Thus, treatment decisions
can be made and discussed with patients while they are still in the office.
Patients say they like the convenience of point-of-care testing, too.
Results from the Prothrombin Office-Testing Benefit Evaluation (PROBE) study
indicate that patients prefer fingerstick PT/INR tests with a portable
monitor over venous lab draws.1,12

… [S]ystematic anticoagulation management may reduce the indirect costs of patient management … [and] it may actually increase revenue.

That preference does not have to come at the expense of
accuracy. Extensive evaluation of the accuracy of portable, office-based
monitors for PT/INR testing indicates that the results are essentially
equivalent to what would be expected from a central laboratory.1,10,11,13
Perhaps most importantly, office-based PT/INR testing can provide a
greater degree of satisfaction to physicians, nurses, and patients than
conventional lab-based testing — and “satisfaction” may be the most critical
component in determining patient adherence to therapy and, therefore,

Greater efficiency

Conventional lab-based care of anticoagulated patients
can involve significant direct and indirect costs — often including
extensive chart activity and follow-up phone contact with the laboratory and
the patient. There can also be additional medical costs and liability
concerns if the office or clinic does not track patients accurately and
perform timely follow-up. As a result, making anticoagulation-patient
evaluation and treatment easier and more efficient through the use of
patient-management software is important from both a financial and a
practical standpoint.

In one workflow process-flow analysis, median turnaround
time (from initial blood draw to patient notification of test results) was
eight minutes for clinics doing PT/INR testing with a point-of-care device,
compared to 498 minutes (eight-plus hours, with a range of 22 minutes to 23
days) for clinics using outside laboratories.3 In the PROBE
study, switching to point-of-care testing significantly reduced the nursing
time required for each patient, as well as the workload in medical records.1

Potentially lower costs

By streamlining both the data-management and the
patient-care components of warfarin therapy, systematic anticoagulation
management may reduce the indirect costs of patient management.4
In addition, it may actually increase revenue. In one study, managing
patients with computerized decision support and an optimized workflow at the
point of care enabled a university-affiliated primary-care clinic to:

  • capture additional revenue of more than $320 per
    patient per year; and
  • reduce labor-related overhead costs by approximately

Because systematic anticoagulation management can be more
effective than routine care, the costs of care for patients can be reduced
as well. One extensive economic analysis estimated that the total cost
associated with routine medical care for atrial-fibrillation patients on
oral warfarin therapy was nearly twice as high as the cost under systematic
anticoagulation management, in part due to the costs related to adverse

A closer connection to patients

Adopting systematic anticoagulation management at the
point of care allows healthcare professionals to potentially lower their
costs for managing patients on oral warfarin therapy, increase their
revenue, and improve patient satisfaction. It also can give healthcare
providers the time and information they need to focus on specific patient
needs and manage anticoagulant therapy effectively, resulting in fewer
adverse events and a higher level of patient care.


  1. Giles TD, Roffidal L. Results of the Prothrombin
    Office-Testing Benefit Evaluation (PROBE). CVR&R. 2002;23:27-28,
    30, 32-33.
  2. Campbell P, Radensky P, Denham C. Economic analysis
    of systematic anticoagulation management vs. routine medical care for
    patients on oral warfarin therapy. Dis Manage and Clin Out.
  3. Jacobson A, Guilloteau F, Campbell P, Denham C.
    Comparison of point-of-care testing and standard reference laboratory
    testing for PT/INR measurements in patients receiving routine warfarin
    therapy: an engineering work process flow study. Dis Manage and Clin
    . 2000;2.
  4. Wurster M, Doran T. Anticoagulation management: A new
    approach. Dis Manage. 2006;4:201-209.
  5. Spandorfer JM, Merli GJ. Outpatient anticoagulation
    issues for the primary care physician. Med Clin North Am.
  6. The concept of Systematic Anticoagulation Management
    was developed by the Premier Innovation Institute.
  7. Jacobson AK. In: Ansell JE et al., eds. Managing
    Oral Anticoagulation Therapy
    . 2nd ed. St. Louis, MO:
    Facts and Comparisons; 2003:45:1-6.
  8. Ansell JE, Buttaro ML, Thomas OV, et al., and the
    Anticoagulation Guidelines Task Force. Consensus guidelines for
    coordinated outpatient oral anticoagulation therapy management. Ann
    . 1997;31:604-615.
  9. Singer DF. Anticoagulation for atrial fibrillation:
    Epidemiology informing a difficult clinical decision. Proc Assoc Am
    . 1996:8(1):29-36.
  10. Bussey HI, Chiquette E, Bianco TM, et al.
    A statistical and clinical evaluation of fingerstick and
    routine laboratory prothrombin time measurements. Pharmacotherapy.
  11. Kaatz SS, White RH, Hill J, et al. Accuracy of
    laboratory and portable monitor international normalized ratio
    determinations. Comparison with a criterion standard. Arch Intern Med.
  12. Williams JR. A cost-saving method for monitoring oral
    warfarin anticoagulant therapy. Cardiovasc Econ. 1997;9-10. In:
    Giles TD, Roffidal L. Results of the Prothrombin Office-Testing Benefit
    Evaluation (PROBE). CVR&R. 2002;23:33.
  13. CoaguChek XS system package insert.
    Indianapolis, IN. Roche Diagnostics Corp., 2006.

Tim Huston is director of Marketing for Professional
Diagnostics-Physician Office Lab at Roche Diagnostics Corp. in