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Home monitoring of ‘blood thinners’ is effective
People on anticoagulation treatments like warfarin are less likely to suffer blood clots it they do their own INR tests at home, according to new Oxford University research
1st December 2011 - For around a million people in the UK who take anticoagulation treatments like warfarin, regular trips to the GP or clinic for INR blood tests are a normal part of life. Now Oxford University research suggests they could do the tests safely and conveniently at home, and it would also nearly halve the risk of suffering blood clots.
Anticoagulation therapy tablets are usually prescribed for conditions such as cardiac arrhythmias, artificial heart valves or a previous history of blood clots. Treatment doses are adjusted according to blood test results. Too high a dose can lead to excessive bleeding, too low risks blood clots that may result in deep vein thrombosis, stroke and heart attack.
Research published online first in the Lancet suggests home testing is safe and effective, and the person who lead the research tells us anticoagulation (‘blood thinning’) treatment home monitoring is as straightforward as using a blood glucose meter and requires a finger stick of blood.
A stroke charity says wants patients to be offered home monitoring, while a heart charity cautions it shouldn't encourage patients to "play doctor" with their medication.
Anticoagulation therapy study
Researchers expect the demand for anticoagulation treatments to rise as the population gets older, and that will put extra pressure on the NHS to offer regular testing.
To provide more evidence of the benefit of self-monitoring, a team led by the University of Oxford looked at patient data from high quality clinical trials which compared self-monitoring with conventional care. They found self-monitoring can improve the quality of anticoagulation and be more convenient for patients.
Overall, self-monitoring reduced the risk of blood clotting events by 49% compared with the usual care. In under 55s, the likelihood of developing these thromboembolic events was reduced by two-thirds and in patients with a mechanical heart valve their risk was halved.
However, the rate of bleeding complications was similar in both groups and self-monitoring did not have a major effect on deaths.
The risk of complications in very elderly patients was not affected by home testing, despite their higher risk of major bleeding, which suggests age should not be a factor in deciding who should get home test kits.
Simple finger prick test
The research team was lead by Dr Carl Heneghan from the University of Oxford. He's director of the Centre of Evidence-Based Medicine at Oxford and a GP. He tells us by email: "Managing chronic disease is an important and costly element of health care which accounts for about 80% of GP consultations. The test is as straightforward as a blood glucose meter and requires a finger stick of blood.
"It is possible to empower patients not only to self-measure but also to self-adjust their therapy."
Dr Heneghan says current management of oral anticoagulation treatment is often done badly, with about 40% of INR results outside target ranges. "Self-monitoring has been promoted in the NHS as a way of improving chronic disease management which empowers patients," Dr Heneghan tells us.