The paper has been drafted in response to increasing patient demand for self-management opportunities and reviews the available scientific evidence to support this form of testing. Self-management involves a patient using a portable coagulometer to measure ‘the time it takes their blood to clot,. known as the International Normalised Ratio (INR) and administering an anti-clotting agent such as warfarin to keep their INR level within a recommended range.

Among the paper’s recommendations are that patients undertaking self-management must be. trained by a competent healthcare professional and should remain in contact with a named clinician, Patients should only use a coagulometer approved by the UK Medical Devices Agency (MDA) or other expert body, and the clinic responsible for the patient’s care should conduct regular quality control tests with the device. To date, the MDA has approved three portable coagulometers.

The most commonly used is the CoaguChek® S. a simple-to-use photometer manufactured by Roche Diagnostics. The meter gives accurate and reliable results in just one minute from a tiny blood sample (around 10 @) which is placed on a test strip and inserted into the machine. The CoaguChek® S is lightweight and portable and holds up to 60 test results in the memory which are retained even if the batteries die or are removed.

OAT is a necessary treatment for people at increased risk of potentially fatal blood clots, such as those with atrial fibrillation (AF), mechanical heart valves, thrombophilia or deep vein thrombosis (DVT) This amounts to around 750,000 people in the UK. The principal anticoagulation agent is warfarin, which many people have to take on a daily basis for their lifetime. Its administration requires a great deal of expertise since warfarin is subject to drug-drug, drug-disease and drug-food interactions, all of which can cause unexpected variations. If the INR is too low blood clots may not be prevented and the individual can be at risk of a stroke, and if it is too high there is a greater risk of excessive bleeding and a possible haemorrhage

Traditionally patients attend a hospital outpatient clinic for the monitoring of their INR level and subsequent administration of warfarin. However the paper estimates that the number of people requiting OAT could rise sharply in the next few years. Currently almost two-thirds of patients with atrial fibrillation remain unidentified. Were they to be found, there could be around 2.5 million people in need of regular monitoring and treatment, placing a great strain on hospital clinics.

As a result patient self-management of INR levels has become an attractive option. It gives patients the flexibility to test their TNR level and instantly adjust their warfarin dose wherever they are whether at home, at work or on holiday. It also eliminates the need for time-consuming visits to hospitals which can be disruptive to daily routines. The British Cardiac Patients Association (BCPA) and Children’s Heart Federation (CHF) represent the majority of warfarin-dependent people in the UK. In response to the increasing interest in selfmonitoring both organisations are involved in a campaign to enable warfarin-dependent individuals who self-monitor to purchase test strips on prescription.

The new paper is intended as an addition to evidence-based guidelines for the therapeutic management of warfarin which were published by the British Committee for Standards in Haematology (1999). The paper's authors recommend their findings be revised in April 2002.