1. Pillars of U.S. Physician Office Testing
Prothrombin Time
(PT/INR)
COAGULATION TESTING HAS A SPRAWLING PRESENCE in IVD markets as it is able to
be performed in virtually all segments, similar to blood glucose testing. The most common
coagulation test is prothrombin time (PT) and its relative score indicated through the
international normalized ratio (INR) (commonly referred to together as PT/INR), which can be
performed in clinical labs, hospitals, physician offices, clinics,
ambulatory care, and even homes. The ubiquity of the test is a result of
its widespread use in monitoring patients using the anticoagulant drug
(or ‘blood thinner’) warfarin to reduce the chance of blood clots. The
miniaturization and simplification of PT/INR test devices has allowed
for coagulation testing at the point of care (POC) including near-
patient, primary care settings as well as patient homes with prescription
self-testing kits.
An extensive review of secondary sources and regulatory filings reveals that PT/INR is the third
most-commonly performed test in U.S. physician office laboratories (POLs) behind only dipstick
urinalysis and the complete blood count (CBC). The test is also among the most-performed in-
office tests in other developed nations with significant POL segments such as Switzerland and
Germany. With over 4 million warfarin patients at any one time, the United States represents the
largest national coagulation test market in the world. Kalorama Information estimates that
approximately 20 million POL PT/INR tests are performed in the United States each year.
As an in vitro diagnostics (IVD) market segment, coagulation represents a broad portfolio of
tests used to assess complex processes behind blood flow and clot formation and regulated by
multiple enzymes and proteins. Coagulation tests also include tests for fibrinolysis (the
degradation of fibrin and dissolution of blood clots) and platelet aggregation. The entire global
coagulation test market is over $1 billion in revenue with the majority represented by PT/INR.
20 million POL
PT/INR tests are
performed in the
United States
each year.

2. The high volume of PT/INR testing in the United States is attributable to the drug warfarin
(brand name Coumadin) prescribed over 30 million times in the country each year. The drug is
prescribed on a long-term basis to individuals with excessive blood clotting, but is also used for
patients with atrial fibrillation, artificial heart valves, deep venous thrombosis, and pulmonary
embolisms. Regular PT/INR testing is critical to ensuring a patient’s warfarin dosage keeps them
in a narrow window of clot prevention (defined by an INR range) between clotting and excessive
bleeding.
The U.S. POC coagulation test market – over 75% of represented by PT/INR tests – includes
tandem end user segments for self-testing and professional POC or POLs. The two segments use
similar test devices differentiated by enhanced data management capabilities and additional
result parameters. Leading companies in the POL PT/INR test market include Roche Diagnostics
(CoaguChek line of devices and accessories), Alere (INRatio 2 PT/INR Monitoring System), and
ITC (ProTime system). While PT/INR self-testing (or over-the-counter [OTC] PT/INR) has seen
superior growth in recent years, the professional POC PT/INR market – including POL sales – is
significantly greater in terms of sales. The future of the professional POC PT/INR test market
will depend upon the incorporation of additional coagulation parameters onto panels performed
on small dedicated analyzers.
FOR MORE INFORMATION:
For more information regarding physician office laboratory (POL) markets, please consult
Kalorama Information’s Physician Office Laboratory Testing Markets Worldwide available with
an upgrade to the updated edition to be published soon.