A New Standard of Care for Improving Patient Outcomes
Based upon a large body of supporting clinical evidence, in 2008 CMS approved PT/INR self-testing for the following warfarin oral anticoagulation indications:
The benefits of self-testing have been clearly documented in published studies, the findings of which can be accessed from the links found below.
When properly prescribed, INR self-testing:
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Oral Anticoagulation Patient Self Testing: Consensus Guidelines For Practical Implementation

Warfarin's narrow therapeutic range, variable biological effects, and potential for food and drug interactions present challenges in managing oral anticoagulation therapy with warfarin. Patient self-testing has been shown to result in significant benefits for patients and their families, health care practitioners, and health care systems.
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Highlights of this October 2008 article in Managed Care include:
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Rationale for Wider Implementation of Patient Self-Testing
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Patient Self-Testing Costs and Related Reimbursement
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Practical Guidelines for Implementation of Patient Self-Testing
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Summary of Consensus Panel Recommendations
Published studies support self-testing for appropriate patients
Increase time in therapeutic range.
A randomized study of 365 patients on warfarin therapy demonstrated that those who self-tested were in range 56% of the time while patients who received usual care were in range only 32% of the time. (Byeth RJ et al. Annals of Internal Medicine 2000;133:687-695)
Self-Testing Can Increase Time in Range

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A summary of the results of published studies reviewed by CMS in their 2001 National Coverage Decision for PT/INR self-testing.
Clinical Evidence Supports More Frequent Testing
Time in Therapeutic Range
by Frequency of Testing
| Study |
TTR |
Frequency |
| Gottlieb 1994 |
50% |
25 Days |
| Horstkotte 1998 |
59% |
19 Days |
| Cannegeiter 1995 |
61% |
18 Days |
| Ansell 1995 |
66% |
16 Days |
| Palaretti 1996 |
68% |
15 Days |
| Ansell 1995 |
89% |
13 Days |
| Horstkotte 1998 |
92% |
4 Days |
*CMS National Decision Analysis, September 2001
For more information and a copy of CMS CPT codes and guidelines, click here.
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Chart illustrating the results of studies showing the correlation between frequency of testing and therapeutic range.

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Lower risk
An analysis of studies on patient self-testing (PST) revealed that "patients capable of self-monitoring their warfarin therapy could benefit from a one-third reduction in death from all causes." (Henagen C. et al. Lancet 2006; 367:404-11)
Weekly Self-Testing Can Improve Patient Outcomes

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Long-term benefit
A ten year follow-up of the ESCAT (Early Self-controlled Anticoagulation study (Koertke H et al. Ann Thoracic Surg 2007; 83:24-9) demonstrated a 33% increase in survival compared to conventional therapy.
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Reduce rate of adverse events
The risk of adverse events increases significantly the further a patient's INR level strays from the prescribed therapeutic range.
Adverse Event Rate

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Positive impact on costs
This chart illustrates the average costs in 1998 associated with the most common anticoagulation-related complications and unfavorable outcomes. The anticipated reduction of these costs is fundamental to the growing acceptance of patient self-testing, which on a practical basis enables more frequent testing, and more timely management of therapy.
Cost Impact Due to Infrequent Monitoring
Cost Associated with Mismatched Anticoagulation
|
| |
Approximate Cost Estimates |
| Bleeding Event |
Thermoboembolic Event |
| Resolution |
$4,000 |
$6,000 |
| Death |
$8,000 |
$12,000 |
| Long-Term Morbidity |
$14-$24,000 |
$21-$26,000 |
|
Adapted from Eckman, MH et. al., Chest, November 1998
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