Satisfaction of Patients with Nonvitamin K Anticoagulants Compared to Vitamin K Antagonists:
a Systematic Review and Meta-analysis
Oral anticoagulation (OAC) is commonly used to prevent or treat thromboembolic events
in patients with conditions such as atrial fibrillation (AF) and venous thromboembolism
(VTE). Until 2010, vitamin K antagonists (VKAs) were the only available type of oral
anticoagulant. While VKAs are effective when used correctly, with a time in therapeutic
range (TTR) of 70% or greater, they have drawbacks. The need for regular monitoring;
concerns about remaining within a preset international normalized ratio (INR) range
and achieving high proportion of TTR; drug, food, and alcohol interactions; and the
possibility of recurrent dose adjustments may negatively affect patients' quality
of life (QoL) and satisfaction with treatment. This, in turn, can have an influence
on patients' adherence and persistence rates. From a clinical perspective, reduced
treatment adherence and persistence can also influence physicians' willingness to
prescribe OACs.
Non-VKA OACs (NOACs) have overcome some of the inherent limitations associated with
VKAs, having fewer drug and food interactions, a consistent dosing regimen, and a
stable pharmacokinetic profile, hence requiring less frequent monitoring (periodic
renal function testing only). It is worth acknowledging that some patients may feel
that regular INR monitoring and the associated contact with health professionals is
preferable, as this may offer an added sense of security. However, NOACs appear to
present a welcome solution to some of the practical issues associated with VKAs, which
have been shown to affect treatment satisfaction.[1]
[2] Unsurprisingly, NOACs have been increasingly used in clinical practice, generally
offering relative effectiveness, safety, and convenience compared with VKAs and leading
to many prescribers switching from VKA to NOACs in real-world practice.[3]
[4]
[5]
[6]
The study by Katerenchuk et al in this issue of Thrombosis and Haemostasis
[7] suggests that patients prefer NOACs over VKAs. Their systematic review and meta-analysis
included four randomized controlled trials and 16 observational studies, with a total
of 18,684 patients receiving OAC for either AF or VTE and demonstrated that, compared
with patients treated with VKAs, those treated with NOACs reported less burden and
greater treatment benefits. Participants who switched from NOACs to VKAs also reported
a reduction in treatment burden and patients' global satisfaction was improved by
treatment with NOACs relative to VKAs.[7] Participants reported that NOAC treatment was less burdensome, more convenient,
and more effective than VKA treatment. Overall, the systematic review by Katerenchuk
and colleagues suggests that patients are more satisfied with NOAC treatment relative
to VKAs, largely due to reduced treatment burden.
The systematic review and meta-analysis were robustly conducted, with study selection
and data extraction performed independently by two researchers. Risk of bias was independently
assessed and observational studies with high risk of bias scores were excluded from
the meta-analysis. However, there was considerable heterogeneity between the included
studies and outcomes relied on self-reported patient data, which introduces potential
bias into the results. None of the subgroup analyses were statistically significant[7] and there was no significant difference in patients' overall perception of NOACs
versus VKAs when assessed using different satisfaction scales.
An important element of long-term anticoagulation treatment is adherence and persistence.[8] It is hoped that greater patient satisfaction with OACs can help achieve this, as
patients who are satisfied with the clinical effects and practical aspects of their
medication should ideally be more willing to adhere and persist with that medication.
Higher treatment satisfaction scores were associated with better adherence to OACs
amongst Australian patients with AF.[9] Reducing treatment burden can also promote better adherence and persistence. AF
patients appear to rate their treatment burden as high, with one in five AF patients
questioning the sustainability of their treatment as a result.[10] Risk of non-adherence among patients with AF was significantly lower among participants
taking a NOAC compared with those taking a VKA (p < 0.001).[11] A recent Korean study exploring adherence to NOACs in a single cardiology department
reported 92% adherence (measured as ≥80% prescribed doses taken).[12]
It is important to remember that the same treatment regimen may be rated as having
different treatment burdens by different patients. A patient's diagnosis, demographic
factors, and comorbidities all affect how that patient interprets OAC-associated treatment
burden ([Fig. 1]). In Katerenchuk et al's systematic review, there were considerable differences
between the AF and VTE patient groups.[7] Patients with VTE were an average of 15 years younger than patients with AF, and
there were more men in the AF group. Furthermore, not all VTE patients required lifelong
OAC treatment, which is an important distinction given that patients' adherence to
OAC tends to reduce over time.[13] A personalized approach, whereby clinicians regularly assess the impact of a specific
treatment on the individual patient, is therefore needed[14] and various tools are available to assist physicians with their assessment of patients'
disease burden and treatment satisfaction levels.[15]
Fig. 1 Factors contributing to effective management of atrial fibrillation.
However, the relationship between treatment satisfaction levels and adherence rates
is complex. A French study[16] that assessed AF patients' treatment satisfaction, adherence to treatment, and QoL
scores reported mixed findings: patients' satisfaction with NOACs was significantly
higher than their satisfaction with VKAs (p < 0.001). However, the greater patient satisfaction with NOACs did not translate
to better medication adherence or increased QoL scores (p = 0.72 and 0.29, respectively). Among patients with VTE, it has been reported that
adherence was not influenced by either OAC-associated QoL scores or practical concerns.[17] It appears that the perceived ease of taking NOACs versus VKAs does not necessarily
always translate to better adherence rates.
What does this mean for clinical practice? Given that many patients, particularly
those with AF, require long-term OAC, physicians and other health care professionals
need to optimize the likelihood of patient satisfaction with, and understanding of,
treatment to increase medication adherence and persistence. Any treatment plan needs
to be realistic, both in terms of its treatment outcomes, which should be discussed
with the patient and incorporate patient's views, and treatment goals and be mindful
of its practical demands of the treatment regimen on patients. Ideally, any treatment
regimen would try to minimize the negative impact on a patient's QoL.[14] Improving patients' understanding of their disease and the benefits/risk of treatment
can help to minimize/offset treatment burden because appreciation of the necessity
of the treatment can result in acceptance of the associated treatment burden and reduce
dissatisfaction. As highlighted in the new European Society of Cardiology guidelines
on the management of AF,[18] the key to improving patient outcomes, including patient satisfaction with treatment,
is a patient-centered approach to the management of chronic disease.
