about Self-testing

Self-testing of oral anticoagulation therapy (OAT) requires confidence and responsibility from people on warfarin.

People who wish to self-test must be motivated to do it. There are no upper age limits, and parents can take charge for their children. You do, however, need to be manually dextrous and have reasonable eyesight. You need to have confidence in yourself and want to take an active part in your own health care.

We are often asked if self-testing is as good clinically as visiting the anticoagulation clinic. Self-testing should be just as good. Studies have shown that people self-testing their own oral anticoagulation therapy stay within their therapeutic range more of the time and have less thrombotic (blood clots) and less haemorrhagic (bleeding) complications than those who visit anticoagulation clinics as their only form of monitoring.

It is important that you talk to your Haematologist, GP or Anticoagulant Nurse about your wish to self-test. You will need their support for some initial training and you will need to arrange with them how you will contact them if you are outside your therapeutic range and how often you will need to go to the clinic to have a venous test for comparison. Some Health Care Professionals can be initially cautious; this might be because they are not familiar with the concept of self-testing.

Some people might find that they are discouraged from self-testing. AntiCoagulation Europe has produced a resource pack designed to help you overcome this and possibly change decisions. Please see the publications and leaflets page for details.

Sometimes, when self-testing, the INR result that you get at home might be slightly different from that obtained at the hospital. This is because the INR result at the hospital is based on a laboratory test called the Prothrombin Time and the result might depend on the experience and diligence of the technician performing the test as well as the quality of the reagents being used. More laboratories are now using automated instruments which helps to standardise results. However, it is still likely that if you sent the same blood sample to two different hospital laboratories you would receive two different results. You might have heard about patient self-management and wonder what is the difference between self-testing and self-management?

With patient self-testing of oral anticoagulation therapy you test your INR at home, but contact your Health Care Professional to adjust your warfarin dose.

In patient self-management of OAT you test at home and then adjust your own warfarin dosage within the limits set by your Doctor.

At present there are two self-testing monitors for use by patients that have been passed by the regulatory authorities in the UK.

One the CoaguChek XS by Roche Diagnostics - get details by phoning 0808 100 7666.

The second one is the INRatio by Sysmex details on 0870 902 9210.

Both devices cost £399.

As other monitors come onto the market we will update the information on this page.