Guidelines for implementation of patient self-testing and patient self-management of oral anticoagulation. International consensus guidelines prepared by International Self-Monitoring Association for Oral Anticoagulation
Introduction
Oral anticoagulation with coumarin derivatives is prescribed to a steadily increasing number of patients as life-long therapy for indications such as mechanical heart valves, atrial fibrillation or inherited/acquired thrombophilic disorders. In addition, oral anticoagulation therapy has been shown to effectively prevent arterial embolism in a wide variety of clinical conditions [1], [2], [3].
The ability to maintain patients within a desired therapeutic range required for oral anticoagulation therapy is a challenge due to two main factors. These are the narrow pharmacologic therapeutic range of the coumarin derivatives, and the variability of their biological effect [4]. This variable dose response results in difficulties in initial dose selection and stabilisation, as well as long-term difficulties in maintaining stability.
It has been shown that improved anticoagulant control results in improved outcomes, with a decrease in the incidence of bleeding complications and thromboembolic events [5]. It is, therefore, essential to maintain close control of the intensity of anticoagulation in order to minimise the adverse thrombotic and haemorrhagic events which occur with under- and over-anticoagulation [6].
Patient self-testing (PST) and patient self-management (PSM) of oral anticoagulation potentially offer further advantages over other approaches. PST is when a patient determines his/her own INR, with dose regulation by the physician; PSM is when the patient is responsible for INR determination and for dose adjustment within given limits, as demonstrated by Cosmi et al. [7].
PST and PSM are not new modalities in chronically ill patients. Regular metabolic monitoring and adjustment of the insulin dose and diabetic diet are accepted worldwide in well-trained diabetic patients and are indispensable parts of diabetic therapy. Patients on long-term oral anticoagulant therapy now also have the option of PST/PSM. There are currently over 100,000 patients performing PST/PSM of oral anticoagulation in Germany alone and a significant amount of information has been collected from these patients over the last few years.
This document has been prepared in order to provide health care professionals involved in initiating and monitoring oral anticoagulation therapy with guidelines for the provision of safe and effective Patient self-testing/self-management of oral anticoagulation. This consensus has been derived from the results of published clinical studies in selected groups of patients, together with extensive experience in clinical practice. It has been developed and agreed upon by specialists with considerable experience in this field as being the best current practice in terms of PST and PSM.
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Usual care vs. anticoagulation clinic care vs. patient self-testing/self-management
Most patients receiving chronic oral anticoagulation today are managed by their own physician, along with all other patients in their physician's practice. There is no organised programme of management, education or follow-up. Only a few studies have specifically assessed clinical outcomes in this ‘usual care (UC)’ model of management (Table 1) [8], [9], [10], [11]. These studies indicate a rate of major haemorrhage of at least 7–8% per patient year of therapy. There is a similar rate of
Patient self-testing and patient self-management
There is potential for further simplifying and improving anticoagulation management by point-of-care (POC) testing. Since the late 1980s, several devices have been introduced or are in development (Table 4) [28].
These instruments are based on clot detection methodology using thromboplastin to initiate clot formation, while the end-point of clot detection varies from instrument to instrument. Although limitations of these instruments have been described, POC instruments have been tested in a
Quality of life
As well as improving TTR and reducing the number of potential complications associated with oral anticoagulant therapy, improvement in quality of life is an important benefit which has been observed with PSM [38], [45], [52].
Cost-effectiveness
It has been shown that PSM can be cost-effective in the longer-term. While the initial costs of PSM are higher than those for laboratory monitoring of INR due to the cost of training and providing the coagulation monitor and test strips, several studies [53], [54], [55] suggest that PSM is the most cost-effective method of monitoring patients on oral anticoagulation therapy. In a GELIA sub-study [56], the reduction in costs associated with the 30% reduction in severe complications and the 20%
Suitable patients
Patient self-testing/self-management should be considered in patients who are on long-term oral anticoagulation with artificial heart valve prosthesis, chronic atrial fibrillation, thrombophilia (e.g. after recurrent deep vein thrombosis in the leg and pulmonary embolism) and post-myocardial infarction with impaired left ventricular pump function, including advanced congestive cardiomyopathy.
Various studies have found that, as with self-testing and self-management of insulin-dependant diabetes,
Suitable coagulometers
The coagulometers currently available differ in their physical methods of measurement and in their degree of automation (Table 4). Easy, portable, fully automated coagulation monitors have now become available which allow the reliable determination of the PT, expressed as INR, from one drop of capillary whole blood from a fingerstick [28].
Specific devices shall not be reviewed in these guidelines due to the variations in devices available in different countries. It is sufficient to say that all
Education and training
Education on the theoretical and pharmaceutical aspects of anticoagulation is a fundamental requirement for all patients on anticoagulant therapy; training on point-of-care INR testing is essential for those patients in PST/PSM.
Education and training infrastructures will develop differently in each country, depending on local circumstances. However, it will require the development of resources to train the trainers, as well as the patients.
Training the trainers
In order that patient training can be successfully achieved, health care professionals who train patients must themselves be trained in the management of anticoagulant therapy and have practical knowledge of PST/PSM devices. There is a considerable amount of comprehensive material already available for trainers. This material should be used as a model wherever possible since relevant standards have already been set and training courses evaluated in clinical practice (e.g. ASA booklet).
Training
Training the patients
Providing an appropriate education programme is an important part of PST/PSM.
For self-testing, the main goal of training is to teach patients practical skills which enable them to achieve accurate INR results. This must include operation of the monitoring device and finger-pricking technique.
For self-management, the main goal is for patients to be able to report INR data, as well as clinical observations regarding their oral anticoagulant therapy, to their health care provider. Furthermore,
Monitoring of PST/PSM
Despite the ability of patients to self-test/self-manage, adequate clinical support remains essential. On-going education, advice in cases of sustained lack of anticoagulation control and advice on interruption of therapy in cases of bleeding or the need to undergo an invasive procedure are, amongst others, all issues which must be considered. The anticoagulation clinic can play an important role in overseeing such organisation.
To provide a methodical guarantee of the reliability of PST/PSM,
Summary of consensus
A significant number of patients undergoing lifelong oral anticoagulation therapy are eligible for PST/PSM. After structured training by trained health care professionals, suitable patients are in a position to determine their anticoagulation intensity accurately and reliably and selected patients are also able to adjust their dosages accordingly.
Recent technical developments have produced high-precision, user-friendly coagulometers. Patients are able to achieve a stable anticoagulant level
Acknowledgements
The following companies have supported ISMAA by unrestricted educational grants: Avocet, Hemosense, LifeScan, Medtronic, Roche Diagnostics, St. Jude Medical.
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