In the present study, we evaluated the factors
associated with medication non-adherence in terms of
motivation and knowledge levels among HD-dependent
patients. Our study results demonstrated that the ratio
of low-motivated patients was 17.2% and the ratio of
patients with a low level of knowledge was 11.9%.
Hypertension and being employed were found to be
associated factors of medication non-adherence in
patients receiving HD.
In the literature review, we found only one study
comparable with our ratio of patients with a low level
of motivation and knowledge. The ratio of the patients
with a low level of motivation (17.2%) and knowledge
(11.9%) in our study were higher, compared to the
study of Ozturk et al.[12] (13.7% and 8.8%, respectively).
A large number of studies have shown that HD
patients with comorbidities indicate a low level of
adherence.[3,13,14] In our study, we investigated HT and
DM, which are the most commonly seen comorbidities in these patients. Consistent with the results of recent
studies, we demonstrated that patients with HT were
less motivated, consequently less adherent to medication
therapy. Since all of the patients with HT were on
antihypertensive medications, it is unclear whether
they were less motivated due to HT itself or due to
antihypertensive medications. Still, we attribute the
non-adherence to medications. A meta-analysis study
conducted in Australia investigated non-adherence to
antihypertensive drugs in patients on HD and reported
that the drugs potentially contributed hypotension after
dialysis treatment, and patients may not have any desire
to take these medications due to hemodynamic effects
they experience.[3,15] Additionally, a comprehensive
review study from United States showed that
antihypertensive drugs might have unpleasant side
effects and provided limited symptomatic relief;
therefore, the drugs could adversely affect adherence
behavior of patients receiving HD.[8]
Although it did not reach statistical significance,
our study demonstrated that younger age might be an
independent risk factor for a low level of motivation,
consequently for non-adherence to medication therapy.
There are many studies in the literature reporting
that younger age is a predictor for medication
non-adherence.[1,14,16] Possible explanations of this
finding include that younger patients may have not
accepted that they are affected by a chronic disease
and may perceive themselves stronger toward the
possible complications of non-adherence. Besides,
younger patients may have a more prominent feeling
of independence, which can lead to disregard of health
problems, and non-adherence behavior.[17] Studies
have shown that older patients are more aware of
possible complications and have more tendency to be
adherent.[1,14]
In the current study, employed patients had a
low level of knowledge, consequently low level of
adherence to medication therapy, which is similar
to the results of previous studies.[1,6,18] Patients who
are working may often fail to follow their prescribed
medications due to their business and occupational
status. They are more involved in daily living activities
and may not be willing to pay attention to the
requirements of medication therapy, and tend to be
more non-adherent.[1]
Studies on the effect of education level on medication
non-adherence yield controversial results. Although
some studies reported a higher adherence in patients
with a higher education level,[4,7] there are studies that have found no association.[1,14] Likewise, we found no
statistically significant relationship between education
level and medication non-adherence. Of note, patients
may not be able to adapt adequately to medications
due to some psychosocial reasons, despite their high
education level.
A higher number of medication was found to be
a significant predictor of medication non-adherence
in many studies.[3-5] Due to drug interactions and
adverse effects of medications, patients often have
difficulty in following their medication therapy.[3,5]
Additionally, complexity of medication therapy related
to the frequency and dosage schedules is significantly
associated with non-adherence.[3] Nonetheless, we
found no statistically significant correlation between
the number of medication and medication nonadherence
which is probably due to having a relatively
small sample in the present study.
The results of this study have a number of
implications for clinical practice. Healthcare
professionals should be aware of factors associated
with medication non-adherence in this special patient
group, and appropriate adherence improvement plans
should be implemented to increase the effectiveness of
the treatment.
The Case Management Society of America has
suggested adherence guidelines to enhance adherence
to medication therapy among patients on HD and
explained motivation and knowledge improvement
tools in details separately. Long-term benefits of
medication therapy and potential consequences of
non-adherence should be explained to patients with a
low level of knowledge and to their families/personal
caregivers via regular educational programs.[9] Patients
with a low level of motivation should be managed
with motivational interviewing, social support plan,
patient reminder systems, and family motivational
assessment.[9] Additional adherence improvement
methods may reduce complexity of medication therapy,
maintenance of relationship between patients and
healthcare providers, and early diagnosis of cognitive
impairment.[19] Many studies have suggested various
adherence improvement recommendations for these
patients. However, being aware of factors associated
with non-adherence and determining patients’ levels
of motivation and knowledge should be the initial
step in managing non-adherence.
Nonetheless, there are some limitations to this
study. First, medication non-adherence was not
directly assessed within the frame of this study.
The scale used in this study demonstrated the risk
factors of low level of motivation and knowledge
of the patients about their medications, and low
level of motivation and knowledge were associated
with medication non-adherence among patients.
Second, we have a relatively small study group.
The other limitation is that we investigated only
HT and DM, which are two major comorbidities
among patients on HD. Despite the limitations,
this study has a significant contribution to the
literature by highlighting motivation and knowledge
perspectives of medication non-adherence among
patients on HD. Other scales evaluating medication
non-adherence other than MMS were not originally
designed to assess the underlying causes of nonadherence
behavior. However, approaching the nonadherence
problem in the perspectives of motivation
and knowledge is essential to establish appropriate
adherence improvement plans that correspond to
the patients’ specific needs. Still, a limited number
of studies has been published considering these
perspectives of medication non-adherence. Our
study, thus, promotes researchers to focus on patients’
motivation and knowledge levels.
In conclusion, HT and being employed were
found to be independent risk factors for a low level of
motivation and a low level of knowledge, respectively.
Based on these results, HT and being employed seem
to be associated factors of medication non-adherence in
patients receiving HD. However, future studies should
be conducted for further understanding of factors
associated with medication non-adherence among
patients on HD. Approaching the non-adherence
problem in the perspectives of motivation and
knowledge is essential to design appropriate adherence
improvement plans.
Acknowledgements
We would like to thank Ahmed Turab Akduman, Ilkim
Yayla, Merve Ornek, and Muhammet Rasit Tutal for their
valuable support with the collection of the data; and Handan
Ankarali from the Biostatistics Department for her valuable
support in statistical analysis.
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.