The estimated number of individuals with
paroxysmal or persistent AF is around 2.2 million
in the United States.[
13] In a study by Uyarel et al.,[
14]
each year 35,000 new cases of AF are diagnosed
in Turkey, and the annual number of cardiac valve
surgeries is approximately 10,000 as reported by
Kervan et al.[
15] Another patient group requiring
tight monitoring of warfarin therapy consists of those
with MCS implantation. Considering the cost of
artificial cardiac devices implanted, as well as the
fact that cardiac transplantation represents the only
therapeutic option in these patients, one may readily
acknowledge the significance of INR monitoring in
these individuals. In a study by Sharma et al.,[
16] 2% of
the general population was found to be on long-term
OAT, corresponding to a population segment of
1.6 million subjects in Turkey. As these figures
suggest, a continuous increase occurs in the number
of individuals on warfarin therapy both globally and
also in our country. Regular INR monitoring in
patients on warfarin therapy helps to prevent simple,
but potentially life-threatening complications. From
an economic perspective, regular visits to a healthcare
facility for INR control are associated with a certain
amount of costs, while treatment of complications
arising from inappropriate use may lead to even larger
costs and loss of productivity.
Our study population attended to our hospital on
an average of 3.0 (IQR: 2.0 to 4.0) occasions within
three months. There were some interesting results observed in this study. As such, 2.6% of the patients
had a delay of approximately one year for their initial
follow-up laboratory assessment, either since these
patients preferred not to spend a considerable amount
of time in waiting queues or due to transportation
difficulty.
A total of 99.4% of 1,259 outpatient visits were
performed only for INR monitoring. Data acquired
from hospital management revealed that the total
number of outpatient visits to the CVS unit were
5,440 during the study period, implying that 23%
of all outpatient visits were performed for INR
measurement alone, leading to a serious workload
for the outpatient setting. When the presence of an
only-INR measurement outpatient clinic (conducted
by the cardiology department) is taken into
consideration, this workload becomes more serious
and overwhelming for clinicians.
According to the data obtained from the Turkish
Statistical Institution (TUIK) as of May 2015, the
rate of employment in individuals between 15 and
64 years of age is 90.5% in the general Turkish
population, compared to an employment rate of only
20.2% for the same age group in our study.[17] These
data suggest that majority of the employed individuals
requiring INR monitoring actually do not attend for
INR measurements, probably due to the difficulties
such as time constraints or getting permission from the
workplace or, in other point of view, these patients are
not able to secure a job due to their conditions.
Since our clinic represents one of the referral
centers in Turkey, individuals residing in locations
other than Ankara province represented 9.4% of
the total study population. Although initially it was
assumed that the majority of these patients had their
follow-up examination in our center due to a previous
surgical intervention performed here, 97.4% were
found to pay a visit to the outpatient facility only for
INR measurements. Contrary to our expectations,
only 2.6% had attended for routine follow-up of the
disease.
A detailed examination of the patients’ history
revealed that after initiation of warfarin treatment,
4.6% of the patients had at least one complication such
as a hemorrhagic cerebrovascular accident or MCV
thrombosis requiring an intervention. Although no
such complications were observed during the study
period, their occurrence would certainly be associated
with the significantly increased costs.
Attendance of patients on warfarin therapy to
a healthcare center for each INR measurement is
associated with a financial and workload burden.
Until now, no studies in Turkey have been conducted
to assess the financial and workload burden on
the National Social Insurance Organization arising
from the care of these patients. In our study, the
total, clinical, and social costs per attendance to our
unit were $31.91, $22.14, and $9.77, respectively.
These figures include complications that can be
prevented with a better regulation of INR. In a
study by Chen et al.[18] from China, the approximate
cost of each INR measurement was found to vary
between $9.8 and $150.5, depending on the distance
between the place of the residency and hospital. In
the aforementioned study, such a wide range of costs
could be accounted for by the higher level of expenses
for transportation and accommodation for patients
coming from peripheral areas, compared to those
coming from the urban locations. However, the cost of
the management of associated complications was not
taken into consideration.
Although conventional INR tests are considered
the gold-standard approach for evaluating the efficacy
of warfarin therapy, technological advances allow
the introduction of more practical and more rapid
measurement devices targeting better monitoring
rates. Such devices enable patients to measure their
INR measurements at home and take more active
responsibility in their treatment, ultimately leading
to improved treatment compliance based on a more
individualized strategy. This, in turn, may result in
a better regulation of the anticoagulant therapies and
decrease the dependency of the patients on healthcare
centers. Comparative studies on such novel devices
versus conventional INR measurements also showed
the reliability of this new-generation POCDs.[19,20]
However, two major questions remain on the use of
POCDs. The first question refers to the provider
and content of the professional assistance, and the
second refers to the possibility that INR measurements
with POCDs may actually be costlier. Wells et al.[20]
found an increased monitoring frequency of INR in
patients using POCDs, while this increase was also
associated with a decreased complication rate. On the
other hand, Sharma et al.[16] found similar average
costs with standard monitoring or home monitoring
systems, while the latter was associated with a reduced
likelihood of thrombogenic events and all-cause
mortality. Considering the cost of the acute treatment of the reduced complication, it may be assumed
that POCDs may prove to be increasingly more
advantageous over time in terms of cost, compared to
standard monitoring procedures. The POCDs may
allow a decreased need for outpatient visits to the
hospital and permit more frequent and regular INR
measurements. In our study, only 7.5% of the patients
had some information on POCDs. Such a few number
of patients who are familiar with POCDs is another
obstacle to home-based measurement of INR by
patients and consequent dissemination of POCDs. We
believe that patients should be informed more about
this alternative measurement tool.
The fact that almost half of the patients visiting
outpatient clinics come to the clinics with attendants
causes an increased cost and loss of labor force,
although 53.7% of the patients were detected to be
outside the TTR values. Besides, 19.7% of them were
not informed about nutrition and complications,
and the way of administration of warfarin were not
explained to 32.8% of the patients. This necessitates
an urgent action plan. We believe that the number of
patients within the TTR values would increase with
a consequent reduction in complications through
patient education about warfarin use and nutrition,
enhanced availability and accessibility to informative
brochures, and clarification of the importance of
regular INR measurements.
Nonetheless, there are several limitations to this
study. Some complications associated with warfarin
due to a short period were unable to be monitored.
Patients who failed to attend to their follow-up
visits for any reasons could not be included and their
social and medical conditions still remain unclear.
Prescription costs were not able to be considered in
this study, as the patients were not willing to wait for
submitting these data after receiving their results and
prescriptions. Economic and social burden analyses
could not be performed for patients requiring home
care. Also, patients using POCSs were unable to be
followed, as they did not attend to the outpatient
clinic.
In conclusion, conventional INR measurements
have a significant social and economic impact on
patients, while they are associated with a significant
increase in workload and loss of productivity from
the perspective of the healthcare provider. We believe
that increased availability of POCDs may play a
role in reducing costs associated with laboratory measurements and complications, and also improve
patient compliance with the treatment. However,
further studies are warranted to elucidate this issue.
Declaration of conflicting interests
The authors declared no conflicts of interest with respect
to the authorship and/or publication of this article.
Funding
The authors received no financial support for the research
and/or authorship of this article.
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