Anticoagulation in Primary Care—A Cross Sectional Study in 14 Heterogeneous Countries

Summary

Background: New oral anticoagulants (NOACs) are predicted to become the new standard treatment for stroke prevention in patients with atrial fibrillation, and may replace vitamin K antagonists (VKAs). NOACs are prescribed less than expected, even though they do not require international normalised ratio (INR) monitoring. In this study we assessed methods for INR monitoring after the introduction of NOACs a in heterogeneous sample of countries. Methods: We asked representatives of the Vasco da Gama Movement, a network of junior and future general practitioners (GPs) in Europe, and WONCA, the World Organization of Family Doctors, to describe the way INR is monitored in their respective countries. Results: Representatives of 14 countries responded. In most countries, the INR is monitored by GPs; in some countries, these patients are treated by other specialists or in specialised anticoagulation centres. In only a few countries, anticoagulated patients monitor the INR themselves. Conclusion: Our study showed several strategies for managing anticoagulation in different countries. In most countries, the INR is monitored by GPs. These consultations offer opportunities to address other issues, such as blood pressure control or medication adherence. These factors may be considered when deciding to switch patients from VKAs to NOACs.

Introduction

New oral anticoagulants (NOACs) have become available in recent years, with the main advantage of a fixed oral dosage, so that the regular assessment of international normalised ratio (INR) values and subsequent dosage adjustment of vitamin K antagonists (VKAs) by a professional was no longer required. Owing to their efficacy and noninferiority to VKAs, NOACs “appear to hit the sweet spot of both improved efficacy and safety” [1] and they were expected to become the new standard treatment for stroke prevention in patients with atrial fibrillation (AF).

However, even though NOACs have been available for some time, opinion remains divided about implementing them. In recent studies several reasons that may explain a lack of implementation were mentioned. First, patients or general practitioners (GPs) may not want to switch, because they are familiar and comfortable with VKAs when INR values are consistently in therapeutic range [1], or because they are comfortable with managing perioperative adjustments in VKA dosing [2]. Second, studies have not shown an increase in the quality of life for patients using NOACs compared to VKA (measured as quality-adjusted life years) [3]. Third, in patients with good or excellent control, switching to NOACs may cause additional risk of major gastrointestinal bleeding or other adverse effects [4]. There are well-validated strategies for the management of bleeding complications, should they occur, when using a VKA [5], but these are currently not available for NOACs.

Another issue complicating matters is that current practice of VKA treatment is different all over the world. To gain insight into current anticoagulation practice and the rationale behind choice of therapy, we undertook this survey to provide an overview of anticoagulant therapy from diverse countries after the introduction of NOACs.

Methods

We assessed the way INR is monitored in a crosssectional study by using a questionnaire. The questionnaire was sent to all members of the Vasco da Gama Movement (VdGM), a network of junior and future GPs, which includes at least one member from most countries in Europe. We also sent the questionnaire to family doctors identified through the World Organization of Family Doctors (WONCA), in order to reach more remote countries. Since the participants in the survey were GPs or trainees involved in international collaboration, the validity of their knowledge of their countries’ systems was relatively high.

The questionnaire was sent at the beginning of October 2012 and consisted of a case of an 80-year-old man with AF who needs anticoagulation treatment because of his CHADS2 score, without any contraindications. Respondents were asked to describe how this patient would be treated in their country and who would do the follow-up.

Results

The questionnaire was sent to 40 different countries of which 14 responded (response rate 35%) (Figure 1). In

Table 1. Different methods of measuring and monitoring international normalised ratio (INR) in 14 countries around the world.

we provide an overview of the description of anticoagulation therapy in these countries. If monitoring was performed in different settings in a country (e.g., by GPs and anticoagulation centres), it was counted once for each measure. INR monitoring is performed by GPs in ten (71%) countries, by other specialists in six (43%), by specialised anticoagulation centres in five (36%) countries, and by the patients themselves in three (21%) countries (Figure 2). Totals add up to more than 100% because some countries had more than one mode of monitoring.

Respondents stated that an advantage of prescribing VKAs was that consultations for managing anti-coagulation also offered opportunities to address other conditions for patients with multimorbidity, which is especially prominent in these patients. While some respondents mentioned higher costs as limiting the use of NOACs, others believed that seeing patients on a regular base is necessary to prevent loss of quality of care (appendix A).

Discussion

Summary of the main findings

This study provided an overview of current anticoagulation therapy management in general practice from 14 different countries. In most countries, the INR is still monitored by GPs, in some countries it is monitored by specialists or at specialised centres and in only a few countries do patients self-manage their VKA dosage. Some respondents were critical of the use of NOACs, since many patients requiring anticoagulation therapy suffer from several other diseases, which can also be addressed during anticoagulation consultations.

Strengths and limitations

The main strength of our study is that we provide an overview from a heterogeneous sample of countries from all over the world. One limitation of our study is that the sample is small and the response rate of 35% was low. However, it does demonstrate the variety of strategies for managing and monitoring anti-coagulation all over the world. Another limitation is that one person described the situation for a country. Since the respondents are active members of their national organisations and participate actively in international activities, they have relatively high knowledge of their health care systems and this should not have influenced results.

Interpretation in relation to current literature

The uncertainty surrounding the choice of anticoagulants is reflected in recommendations in international guidelines [6]. The American College of Cardiology

Foundation / American Heart Association Task Force on Practice Guidelines note “Because of ... the greater risk of non-hemorrhagic side effects ... patients already taking warfarin with excellent INR control may have little to gain by switching ...”. On the other hand, a systematic review including >50,000 patients on NOACs showed a significant reduction in major and intracranial bleeding compared with VKAs [7].

Studies suggest that the accessibility of primarycare practice may affect the efficiency and effectiveness of oral anticoagulation management. Proposed strategies to improve monitoring access in primary care include careful follow-up of patient adherence and missed appointments [8], same-day availability of laboratory results, comprehensive patient education [9], training of other healthcare personnel to oversee monitoring, and various self-care models [10]. Thus, the use of VKAs may still improve, which would further diminish the advantages of anticoagulation drugs such as NOACs that do not require monitoring.

Implications for clinical practice

The management of multimorbidity is a key issue for GPs. The use of VKAs gives patients the opportunity to have regular contact with their GP’s practice, and regular measurement of INR levels provides insights on patient comprehension and compliance. After switching to NOACs, valuable knowledge about adherence may be lost. Therefore, we speculate that switching to NOACs not only affects stroke prevention, bleeding rates, the inconvenience of INR monitoring and costs, but also has an impact on the quality of care of patients with multimorbidity.

Conclusion

Using a global network of GPs, we provided insight into current anticoagulation therapy in 14 countries in different parts of the world. In summary, although several strategies for monitoring INR are being used in daily practice, in most countries primary-care physicians provide INR monitoring. Respondent GPs also raised critical issues about the loss of opportunities to provide additional care to their patients when they visit for INR monitoring, which is especially important since multimorbidity is often prevalent in patients on anticoagulants. This additional factor may be considered when deciding whether to switch from VKA to NOAC anti-coagulation.