Dr. Ansell
Interview: Jack Ansell, MD
Professor of Medicine
Boston University School of Medicine
Vice Chairman for Clinical Affairs
Department of Medicine
Boston University Medical Center
Medscape had the opportunity to discuss laboratory and office-based anticoagulation monitoring with Jack Ansell, MD, Professor of Medicine, Boston University School of Medicine, and Vice Chairman for Clinical Affairs, Department of Medicine, Boston University Medical Center in Boston, Massachusetts. Dr. Ansell is the founder and past president of the Anticoagulation Forum.
* Please review the evolution of point-of-care anticoagulation testing. What have been the major advances in this field?
* What are the potential clinical benefits/outcomes of point-of-care patient testing?
* In Europe, the approach of self-testing and self-management is well accepted. Do you see this approach being more widely utilized in the US?
* Anticoagulation clinics have had a major impact on managing anticoagulation treatment. Describe the role they have played over the last 10 years and the challenges they have faced.
* Are there specific outcome data (clinical, economic) to reinforce the benefits of either of these approaches (anticoagulation clinics or physician office testing) over routine laboratory measurements?
* The demands of our population for anticoagulation testing will continue to grow with the “graying of America.” What does the future hold for anticoagulation treatment and management?
Please review the evolution of point-of-care anticoagulation testing. What have been the major advances in this field?
Dr. Ansell: As we look at the evolution of point-of-care testing, this modality of care started in the mid 1980s with the development of instruments that were able to perform a prothrombin time test from a finger stick sample of blood near the patient instead of sending a venous blood sample to the laboratory. The first instrument became available in 1986 or 1987 and quickly thereafter clinical studies were initiated to determine the value of these instruments as well as their accuracy and precision. At the same time, the instruments began to appear in physicians’ offices and to a very limited extent in patients’ homes for self-monitoring.
From the late 1980s up to the present time there has been, unfortunately, a slow uptake of point-of-care monitoring in the United States as it pertains to home monitoring of the international normalized ratio (INR), or prothrombin time. However, there is extensive use of point-of-care anticoagulation monitoring in physician offices, anticoagulation clinics or other sites.
The major advances in the field of point-of-care testing involved the publication of clinical studies to demonstrate the effectiveness of this type of testing either in the physician’s office or at home and the outcome of greater time in the therapeutic range.
In addition, over the last 20 years, there have been advances in instrumentation. Instruments manufactured today are considerably better than those that were first produced, in terms of their ease of use, electronics, visibility of the results and the ability of patients to use these instruments. In addition, they have been shown to be accurate and precise in their ability to measure an INR.
Lastly, I think the last major advance has been the overall impact on anticoagulation monitoring, whether it’s in the physician’s office, an anticoagulation clinic, or at home. Because of the accessibility to results immediately as well as the ability to determine an INR frequently, there is better care, fewer adverse events, and greater time in therapeutic range. And because of its impact on the overall outcomes of care, I believe it has led to a reduction in the overall cost associated with anticoagulation care.
What are the potential clinical benefits/outcomes of point-of-care patient testing?
Dr. Ansell: The potential benefits of point-of-care testing in the physician’s office has to do with the ability of these instruments to facilitate a process of systematic anticoagulation monitoring, ultimately leading to better outcomes.
Having an instrument allows the physician to have immediate access to results with a patient sitting right there, enabling immediate discussion of the results and instruction to the patient on the next dose of oral anticoagulant. This leads to better patient/physician communication and ultimately to more time in therapeutic range.
There’s also a certain degree of patient empowerment that comes from observing these results and discussing them with a physician as they occur, which also helps to enhance compliance and outcomes. Ultimately this type of care also will reduce some of the work in a physician’s office by eliminating the need to track down results from outside laboratories. In some cases the physician never gets the results, and that leads to problems. Not needing office personnel to make multiple calls to laboratories or to patient homes, not having to give instructions in dose changes over the phone and be concerned about that the patient understands or doesn’t understand the changes, all emphasize the benefits of point-of-care testing.
For the physician’s office, there are economic and clinical studies that have been done to show that overall the cost of care can be reduced, again primarily by improving outcomes and reducing adverse events. The cost differential is beneficial when you consider the time required to interact and call back the patient with results from the laboratory compared to having a brief face-to-face encounter and an immediate turnaround of results with a point-of-care monitor.
Overall, in the physician’s office, I think that point-of-care monitoring really leads to better care and to better outcomes and facilitates a more systematic process for managing these patients.
In Europe, the approach of self-testing and self-management is well accepted. Do you see this approach being more widely utilized in the US?
Dr. Ansell: At home, where patients have greater access to INR measurement, they can monitor their INR on a more frequent and timely basis – timely meaning that when they think they may have done something to alter their INR they can simply check their INR. It gives the patient a certain degree of freedom. It improves quality of life and patient satisfaction. And also consistency of instrumentation is important, because in the real world patients often go to different laboratories, a hospital laboratory, a private laboratory or elsewhere and they’re using different reagents and different instrumentation to monitor their INR. When a patient has an instrument at home, it’s a consistent instrument and reagent combination, which I believe leads to better care.
Patient self-monitoring is something that is suitable for the majority of patients — not every patient, but the majority of patients, and this has been demonstrated through various studies to date. Patients are able to do a finger stick and monitor their own prothrombin time. For patients to actually manage their own dosing at home, that’s a slightly more limited population, but still a majority of patients should be able to do that.
In the United States, this model of care has been very slow to develop. The principle barrier has been reimbursement and approval by Medicare, which sets the standard for other third party payers.
Patient self-testing was not approved for reimbursement by Medicare until the early 2000s, and then it was only for patients with mechanical heart valves who had been on an anticoagulant for at least 3 months, not for the large majority of patients who have atrial fibrillation or other problems.
Right now it is estimated that there are perhaps 10 to 20,000 patients in the United States that are performing patient self-testing at home. This really represents less than 1% of the estimated population of patients on warfarin at the current time in the United States.
In Germany, where self-monitoring and management are really involved with about 25% of the anticoagulated population, over 130,000 patients are doing self-management and monitoring; the factor that made the difference there was probably the early reimbursement for self-monitoring.
But now, with the continued growth in the use of oral anticoagulants, the aging of our population, and the increase in atrial fibrillation and other indications for anticoagulants, there has been a small resurgence in interest and desire to do point-of-care testing at home.
I do see that this type of care and management of anticoagulation will grow over the next several years to reach at least several percent of the affected population in the United States.
Anticoagulation clinics have had a major impact on managing anticoagulation treatment. Describe the role they have played over the last 10 years and the challenges they have faced.
Dr. Ansell: Anticoagulation clinics are by no means new. They’ve been around since at least the 1960s, if not even a little earlier. Their popularity really started to develop in the 1980s and especially in the 1990s, coincident with the growth of use of oral anticoagulants and particularly for atrial fibrillation.
Anticoagulation clinics have benefited the patients on anticoagulants by better management of dosing and better communication and education of the patients than in what might be called a routine model of care, where a physician manages a small group of his or her own patients on anticoagulants, but usually in a less systematic way, without policies and procedures and mechanisms in place to make sure patients are not lost. Anticoagulation clinics are dedicated to this one modality of care.
Anticoagulation clinic management has led to greater time in the therapeutic range, which again is the ultimate goal, and as a consequence fewer serious adverse events. Anticoagulation clinics also, because they take the burden off of the practicing physician, can ultimately lead to an increased percentage of the population on anticoagulants because anticoagulation care often is a fairly complex and labor intensive responsibility. So when you have a clinic that can do this with dedicated personnel such as a nurse or pharmacist, it allows a greater percentage of patients to be treated.
Are there specific outcome data (clinical, economic) to reinforce the benefits of either of these approaches (anticoagulation clinics or physician office testing) over routine laboratory measurements?
Dr. Ansell: There are a number of economic and clinical outcome studies that have been done to show the benefits of anticoagulation clinics. It is well documented in the literature that anticoagulation clinics achieve a greater time in therapeutic range for the patients they monitor compared to routine medical care, and that because of cost savings from fewer adverse events it improves the overall cost of anticoagulation care.
The demands of our population for anticoagulation testing will continue to grow with the “graying of America.” What does the future hold for anticoagulation treatment and management?
Dr. Ansell: The future of anticoagulation treatment and management will continue on its current course with more patients being treated with warfarin over the coming years. The aging of the population is contributing to the increase in the number of patients with atrial fibrillation as well as other problems.
The one thing that will impact point-of-care testing and warfarin therapy in general is the development of new oral anticoagulants. There are currently more than a half a dozen new drugs in phase II and phase III clinical trials. These oral agents have predictable dosing, do not require monitoring, and are given on a once or twice a day basis. Based on preliminary studies, these agents are effective in preventing thrombosis. The real issue is are they as safe or safer than warfarin, particularly in any untoward side effects such as liver impairment, and are they better than warfarin in general.
It will take at least another 5 years or so to determine the results of some of the long-term studies in atrial fibrillation and other indications with these new medications.
I think the number of patients on warfarin will decrease, but there will still be a substantial population of patients on warfarin. There will be certain indications, such as patients with mechanical valves, who are not even being studied yet with these new drugs, that will continue to use warfarin and other anticoagulants.
So I think that warfarin and the need for anticoagulation monitoring will be around for many years to come and will probably never go away, but I think if these other drugs are successful, effective, and safe, that they will impact the population and the numbers who are taking warfarin.
