CADTH 2015 Symposium

1. POC INR Testing
Rural and Remote Session
2015 CADTH SYMPOSIUM
Janice Mann MD
Knowledge Mobilization, CADTH

2. CADTH’s POC INR Optimal Use
Project
Objective:
• To support well-informed decisions about the acquisition
and/or optimal implementation of POC INR technology
• To inform decision makers regarding the accuracy, as well
as the clinical and cost-effectiveness of POC INR compared
with standard laboratory testing, and compared with other
POC INR devices.

3. Background
• Approximately 350,000 Canadians are taking oral
anticoagulation therapy (OAT) – mostly warfarin
• Patients must be monitored for over-anticoagulation
(possibly resulting in bleeding or hemorrhage) and under-
anticoagulation (which could result in blood clots), by
measuring International Normalized Ratio (INR)
• INR monitoring typically occurs every 3-5 weeks in patients
stabilized on anticoagulant therapy, however more frequent
monitoring is required when starting therapy.

4. INR Testing
• The gold standard for monitoring INR is lab testing of blood
obtained by venipuncture, in hospital or at an
anticoagulation clinic.
• Point of care (POC) testing is another way to monitor INR.
• POC testing is testing at or near where a patient is located.

5. POC INR Testing
The aims of POC testing are:
• Convenience for the patient
• Faster test results to the health care provider
• Faster clinical decision-making
• Improved clinical outcomes and reduced health care
resource use

6. POC INR Testing
• The POC INR device is called a coagulometer.
• There are 9 POC coagulometers currently or soon to be
available in Canada
• POC testing for INR involves putting a sample of whole
blood, usually capillary blood from a finger stick, onto a test
strip.
• POC devices and test strips are not currently an insured
benefit in most Canadian jurisdictions, although they may
be available as part of hospital or clinic supply budgets.

7. Options for Implementing POC INR
Patient self-management (PSM)
• Patient self-tests the INR using a POC device, and self-
adjusts the dose of the anticoagulant medication based on
the results using a predetermined algorithm or protocol
Patient self-testing (PST)
• Patient self-tests the INR using a POC device and a
clinician adjusts the dose of anticoagulant medication based
on the results
Clinic-based POC INR testing
• POC testing is performed in a clinical setting such as a
physician’s office or anticoagulation clinic.

8. Questions about POC INR vs. Lab
1. Is POC INR testing as effective as laboratory testing for
determining whether INR is within the therapeutic range?
2. In what healthcare settings are there clinical and cost
advantages or disadvantages for the use of POC INR
testing over laboratory testing?
3. In what healthcare settings are there advantages other
than clinical and cost (for example, access to testing or
convenience) for POC INR testing over laboratory testing?
4. Is there one particular POC device that is superior to
others in terms of clinical, cost, and other advantages?

9. POC INR vs. Lab Testing
What Does the Evidence Say?

10. POC INR – Clinical Review
• The clinical review included 48 articles reporting on
47 unique studies, including five RCTs assessing the impact
of POC INR testing on clinical outcomes.
• Only studies evaluating POC coagulometers approved and
available for purchase in Canada were eligible for inclusion

11. Summary of Evidence - Clinical
Precision and Accuracy:
• For INR values within the typical target therapeutic range (2
to 3.5), POC meters produced results comparable to lab
• Mean difference in INR values between POC INR and lab
was within 0.5 units the majority of the time, with a
maximum average difference of 0.8.
• Strong correlation between POC INR and lab
• However, the difference between INR values between the
two methods may increase at high INR values ≥ 3.5 units.

12. Summary of Evidence - Clinical
Time within Therapeutic Range (TTR):
• POC coagulometers led to an average increase of 6.14% in
TTR compared with lab testing, equivalent to approximately
25 days over the course of one year.
Clinical Outcomes (Adverse Events):
• POC meters included in this review did not lead to a
statistically significant change in the rate of major bleeding
or thromboembolic events or strokes compared with lab.

13. Summary of Evidence - Clinical
Patient Satisfaction and Quality of Life:
• Limited data on patient satisfaction reported preference for
POC over lab testing.
Comparison of POC INR devices:
• Evidence was identified comparing Coaguchek XS,
Coaguchek XS Plus, INRatio, i-STAT, or ProTime to
laboratory testing.

14. POC INR - Economic Analysis
• A cost-effectiveness analysis comparing laboratory testing,
patient self-management, patient-self testing, and POC INR
testing in a clinic setting in terms of incremental cost per
quality-adjusted life-years (QALY) gained.
• An expanded payer perspective that included patient level
costs associated with lab or clinic visits was also conducted
to reflect scenarios in which patient travel costs are
reimbursed by public payers.

15. Summary of Evidence - Economic
• Using retail prices for POC devices ($499 per patient-grade
POC and $2,056 for professional-grade POC), and $8.33
per test strip, lab testing was the least costly option with a
total cost of $7,033 per patient.
• Patient self-management (PSM) emerged as a cost-
effective option ($13,028 per QALY gained compared to lab)
• Patient self-testing (PST) and clinic-based POC were more
costly and less effective.

16. Summary of Evidence - Economic
• When considering patient travel costs for clinic and lab
visits, PSM was the least costly option.
• These results remained robust to variations in estimates of
device costs, frequency of testing, health care provider
costs in various settings, and patient travel time (such as
rural versus urban settings).

17. POC INR – Bottom Line
• POC INR testing with any currently available POC INR
device is an accurate alternative to lab INR testing.
• Patient self-management (POC INR testing + dose
adjustment) is the most cost-effective option, when feasible.
• Patient self-testing with health care provider dose
adjustment may be an option when lab INR testing is
difficult.
• Clinic-based POC INR testing requires careful consideration
of context and costs.

18. POC INR Newsletter
hospitalnews.com/point-care-inr-testing/
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19. POC INR Comparison Tool
Lab INR vs. PSM vs. PST vs. Clinic-based Testing
• Results
• Patients
• Sample for Testing
• Location
• Average Test Frequency
• Healthcare professional required
• Patient or caregiver training required
• Accuracy
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20. POC INR Comparison Tool (con’t)
• Timeliness
• TTR
• Satisfaction/Quality of Life
• Health Outcomes
• Estimated Cost/Patient/Year
• ICER or Cost/QALY Gained
• Cost-effectiveness
• Question/Considerations for Implementation
bit.ly/1FIoEcL
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21. POC INR Costing Tool
• A tool for decision-makers who are considering the
implementation of POC INR technology.
• The tool helps estimate the total costs of PSM, PST, or
clinic-based POC INR testing.
• Allows users to enter setting-specific information regarding
case load, practice patterns, and costs.
bit.ly/1FIoEcL
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