July 6, 2000 -- People who take blood-thinning medications to prevent clots may be able to safely skip some of those repeated trips to the doctor to have their blood checked. A new study finds that patients who monitor their own blood-clotting time and drug dosing at home do just as well as those who have it done by a doctor or lab.
In a study published in the medical journal The Lancet, Dutch researchers found there was virtually no difference between patients who managed their own care at home and those who had it done at a clinic. In some ways, the patients who monitored themselves at home did better than the ones seen at a clinic, and most of them preferred self-treatment.
The most common blood thinner is called Coumadin, and it is taken to prevent blood clots in patients at risk for having a stroke, heart attack, or blood clot in the leg or other part of the body. People taking Coumadin usually go to the doctor to have blood drawn to test their blood's clotting time every few weeks to make sure they are taking the correct dose of medicine. Taking too much Coumadin increases the risk of excessive bleeding, and too little medicine does not protect against clots.
Home management of blood-thinner therapy may give patients more control over their treatment and result in improved compliance in taking the Coumadin, according to study author Manon Cromheecke, MD, of the department of cardiopulmonary surgery at the University of Amsterdam in the Netherlands, and colleagues.
The researchers theorized that since easy and reliable monitoring devices have become available for home use, this might allow patients to take a more active role in their care. They divided 50 patients into two groups. One group monitored their blood levels at home and made their own adjustments in their medication, while the other group had the monitoring done at a specialized clinic. At the end of three months, the groups switched places. The patients who had received care at the clinic now monitored their blood at home, and vice versa.
No significant differences were found between the two groups; in fact, patients appeared to do a little better when they were self-monitoring. Their blood-clotting times were more consistently in the best range for keeping both clotting and bleeding under control.
Julie Hambleton, MD, compares self-management of blood thinners to the way diabetics manage their blood-sugar levels: "Diabetics have much tighter control, since they can monitor themselves at home -- they're not going to come into a clinic four times a day -- so the same aspects may apply to Coumadin therapy." Hambleton, who was not involved in the study, is director of the Hemostasis and Thrombosis Center at the University of California, San Francisco.
She says some of her own patients on blood thinners do self-monitoring. "Patients can safely self-manage and then, like a diabetic, have some guidelines as to when to call in. That's actually how I do it with some of my own patients who have home monitors. They don't call me if they are in the right range, and I have them keep a diary so we can keep track of trends."
On a quality-of-life questionnaire, the study participants also indicated that they were more satisfied with doing their own self-management. And they reported less stress and anxiety when managing themselves than when they were managed by the clinic.
The researchers believe that self-management with blood thinners may be at least as effective as management by a specialized clinic. Self-management, they say, "may be considered as a novel, patient-friendly, and effective strategy to improve long-term treatment with anticoagulant agents."
"This type of study is important for us as [doctors], because it shows that this is very feasible as well as cost saving," Hambleton says. "For example, for Medicare -- they would have to pay up-front costs for the monitoring device, but they would save in the long run because patients would only need to go to a clinic three or four times a year, and they'd have much better control."