Factors Affect to Medication Adherence
Several factors have been shown that hinder patients from taking their
medication as prescribed. World Health Organization (WHO) has
categorized common factors that affect adherence to five different
dimensions.3 The five dimensions of adherence are
socioeconomic, healthcare provider/system, illness, medication, and
patient-related factors.3 As described below, these
five dimensions used in this scoping review to extract the factors from
included studies. Factors that could contribute to medication adherence
among patients diagnosed with MDD are summarized and presented in Table
5. However, studies are not consistent about the relationship between
factors and adherence. Over 33 included studies, 26 of them investigated
the factors that influence medication adherence. The following section
will explore commonly reported reasons and factors associated with
adherence to medications.
Socioeconomic related factors. Language and literacy have been
associated with the adherence level.64 By using
different self-reported assessment methods, medication adherence was
related significantly to income,56,57 level of
education.52,57 Regarding living conditions, Yau et
al25 noted that the type of accommodation associated
with noncontinuous use of AD
medications. Patients whose accommodation in public housing property
that reflects low socioeconomic status was related to noncontinuous use
of AD medications.25 On the other hand, the occupation
of patients has a relationship with an adherence level of medication.
Also, patient occupation in service and farming reported a significantly
high adherence rate than business, housewife, and
students.60
Lack of family support and the nature of the job stated the reasons for
nonadherence.57,65 Studies conducted in different
contexts reported that lack of support from family members, spouses, and
friends was found barriers from delayed initiating AD medication and
continuing
it.24,73 Also, Ho et al24 and Vargas
et al74 noted that social-cultural stigma influences
on adherence, which stigmatizing views held by others in patients’
social circle were depression is a sign of madness and negative personal
characteristics. Moreover, religion and cultural beliefs have been
barriers to medication adherence.24
Healthcare
provider/System-related factors. Accessibility to healthcare services
included long-distance, poor access to healthcare locations, long
waiting time at the clinic, limited time with psychiatric doctor, and
lack of accessible appropriate material influence to medication
adherence. Compared to the short distance, patients who move to the
psychiatric clinic from long-distance five times nonadherent to
medications.22 Ho et al24 reported
that patients who have experienced long waiting times at the clinic and
lack of transportation to healthcare locations hospital resulted in
patients not taking medications. Also, poor of access to different
formats of informational materials in psychiatric clinic influence on
medication adherence, which included lack of verbal and written
instructions and information, use different language in instructions and
information, and use appropriate format for patient with physical
disability (e.g., hearing and visual impairment).64Furthermore, the limited time of follow-up visits with the psychiatrist
in the clinic affects adherence to medication.64
The change of psychiatrists and multiple prescribers every visit affects
the patient’s confidence and trust toward providers, which later
affected their medication-taking behavior,24 and
non-availability of psychiatrists during follow-up one of the reasons
for nonadherence.57 In addition, the satisfaction
level of the patient with psychiatrists is related to
adherence.21 On the other hand, the frequency of
follow-up visits to psychiatric clinic affects adherence to
medications.21,24,34The lower number of visits to
clinics related significantly to a low level of adherence to AD
medications.23,25
Ho et al24 presented the poor communication between
the patient and provider could impede medication adherence. In addition,
inadequate information on medications and disorders, and healthcare
provider guidance related to the low level of adherence (Srimongkon et
al. 2018).57,64 In spite of appropriate information
and guidance, access to medication in facilities are still relating to
continuous taking medications.24,57,73
Illness-related factors. Acute onset of the illness associated
with the early withdrawal was experienced in the patients with
MDD.65 Also, earlier MDD diagnostics minimize the
non-continuous behaviors of AD medication.25 For the
duration of illness, a short duration of illness significant in relation
to high rates of adherence.23 Alekhya et
al21 noted the correlation between low adherent
patients with patients experienced more than a year of illness. In the
same way, the risk of nonadherence to medication in patients who have
been diagnosed MDD for more than two years is high.22Furthermore, the adherence to medication is influenced by symptoms and
the severity of the disease. Lucca et al57demonstrated that patients reported forgetfulness, no improvement, and
deterioration of conditions impaired the adherence to medication. A
phenomenological study reveals that depressive symptoms; forgetfulness,
lethargy, and laziness impair the adherence of AD
medications.73 Similarly, other studies have shown
that somatic symptoms associated with an early dropout of
treatment.65 Furthermore, nonadherent patients are
closely associated with high physical pain.48 De las
Cuevas et al52 have found that patients with a severe
degree of depression related to nonadherent patients. However, the
opposite association between adherence and depression severity, which
clarified that lower depressiveness was significantly correlated with
higher medication adherence rates.23,48 In another
study, the research in Beijing has revealed that few episodes of
preceding depression had a significant impact on medication adherence
that had a positive relationship to increased medication
adherence.56 The number of psychiatric
hospitalizations influence factors to medication adherence. A more
significant number of psychiatric hospitalizations correlated with a
high degree of non-compliance medications have been reported by
Baeza-Velasco et al.48 In addition, in co-morbid
illnesses, included studies have reported that patients with MDD who
comorbid with physical illnesses, alcohol dependence and illicit drug,
and concomitant psychiatric illness negatively interfered with adherence
to AD medications.21,22,24,65,48
Conversely, patients with co-morbid anxiety exhibited high adherence to
medications.56 Patients with a family history of
depression and past history of depression were also strongly in
nonadherence.21 Also, in patients with a suicidal
ideation and attempts, a poor adherence level is also substantially
increased.21,48 Indeed, a cross-sectional study was
performed of patients with bipolar disorder, schizophrenia,
schizoaffective, depression, and other psychiatric disorders at the
psychiatric clinic, which showed that the diagnosis had a major effect
on nonadherence to medications.34
Medication-related factors. According to recent studies,
complex treatment regimens impair adherence significantly. Alekhya and
colleagues21 found out that polypharmacy has a major
impact on adherence; the most significant number patients are not
adhering to a multiple drug system. Also, patients with co-morbidities
discontinue AD medications related to the barrier of pill burden, which
they are taking so many types of medications.24 In
addition, statistically significant is the relationship between the
number of prescription medications and medication
adherence.49,57 Moreover, previous studies stated that
adverse reactions have association with level of medication
adherence.21,25,49,62,64,65,73 In addition,
nonadherence is related to severity and the amount of adverse
effects.52 Ho et al24 reported that
patients have stopped taking medications associated with the experience
of side effects. Other included studies have found that patients with
MDD describe and stated that the majority of reasons for nonadherence
are an adverse reaction.34,57,60
The duration of treatment can also affect adherence to medications.
Findings by using MPR reported that statistically and practically
important the duration of treatment is correlated with adherence to
medication.69 Lucca et al57 noted
that during the first three months of treatment patients continue to
take medication with a significant association with medication
nonadherence. The qualitative study concluded that patients who are
concerned about the long-term effects of AD medications have a negative
effect on the implementation of therapy.73Inconvenient dose regimen may affect medication adherence, which
explained that doses could be needed once a day, twice a day, three
times a day or more than four times a day.73 In other
studies, the cost of medication was a factor for
nonadherence,57 and is correlated substantially with
nonadherence.60 Studies that have assessed adherence
to the prescribed class of medication reported that the type of active
ingredients consumed or formulations and adherence were significantly
related.57,69 However, the most common reason for
discontinuance was the ineffective response of the
medication.58
Patient-related factors. Patient factors associated with
medications adherence represent sociodemographic factors (age, gender,
race, marital status), psychological factors (beliefs, attitudes,
satisfaction, knowledge, psychological reactance, locus of control,
self-stigma, self-motivation, insight, self-management), and physical
(cognitive and behavioral) factors (forgetfulness, the patient’s
personal obligation, carelessness, confusion).
Age considered the predictor of
adherence to prescribed medications, in Spain, adherence to AD
medication was assessed in the two community mental health centers
located on Tenerife Island, and the result was that the likelihood of
adherence to the medication for older patients was
lower.53 A study that has compared the level of
adherence reported lower adherence levels for patients older than 60
years than for patients aged 18-40 years.69 In
contrast, Al-Jumah et al23, found that older patients
had a high level of adherence. In addition, young age patients
significantly associated with noncontinuous use of AD
medication.25
Gender is an important factor in the non-continuing use of AD
medications, with female patients showing a high level of non-continuous
use of AD medications.25 In addition, the energetic
disparity of the male is a statistically important differentiation for
adherence.23 However, race-gender also associations
with adherence, AD adherence difference across four
race–gender subgroups
(African-American women, African-American men, White women, and White
men), white women more likely to be adherent to their AD medication 3.1
times than African-American women.50 Moreover, marital
status exhibits significant differences in the level of medication
adherence. According to Baeza-Velasco et al48 reported
that high adherent patients have a partner.
A patient’s beliefs are influence decisions of medication-taking
behavior, the necessity beliefs of medications associate positively with
adherence to medication; likewise, the beliefs of concern, harmfulness,
and overuse related with nonadherence to
medication.23,49,51,62 The beliefs that psychiatric
medications general harmfulness is in relation to nonadherent
patients.52 Nonadherent patients displayed a high
degree of concern for medications perceived to have potential adverse
effects, such as dependence, side-effects, or accumulation
effects.52 In another study, the belief that the
medication relieves the symptoms, does not relieve the symptoms,
increases the severity of the disease, and the belief that they do not
suffer from a psychiatric illness; these reasons impressed continuous of
treatment.65 In addition, patients have reported
necessity beliefs such as AD that help treat depression, safe for most
patients; it must be taken daily for several weeks to ensure it works,
which positively affects their adherence.64 Also, harm
beliefs that explained that medications are addictive associated with a
low level of adherence.64 Other study presented that
patients showed incorrect beliefs about MDD and AD medications, and harm
beliefs of fear of medication dependence that related to
adherence.24
Indeed, high necessity beliefs significant predictors of high AD
medication adherence which explained through patients’ beliefs that AD
medication could protect against exacerbation of depression; without AD
medication, they will be very depressed; the mental health status will
depend on AD medication.56 Also, negative impact
between the concern beliefs about the AD medications and AD medication
adherence expressed through concern about their long-term consequences,
heavily depends on them, they are a mystery, they disturb
life.56 Srimongkon et al73 reported
that the patients’ beliefs that medication efficacy has a positive
influence on adherence and negative factors on adherence in patients
with concern regarding therapeutic effects and side effects of
medications. Qualitative interviews of the experiences of Latino
outpatients with MDD investigated depression and pharmacotherapy
perspectives, concluded that patients had concerns regarding medications
and depression that may have been perceived as obstacles to treatment
and medication adherence.74
Concern beliefs over the fear of dependence on AD medications, physical
ramifications for taking AD medications, risk of deteriorating
depression and mental health, high dosages of prescription are
hazardous, irrepressible adverse effects, and alternative cures have
less antagonistic impacts than AD medications.74 Also,
concern beliefs about depression
referred that depression is exacerbated and not
relive.74 Other barriers are beliefs about AD
medications use that disagreement with psychiatric advice, which
patients believe that it is the last choice, it is should work
immediately, it is used when feeling depressed and take high doses of
it, and not take when feeling better.74 In addition,
the fear about the medications and from addiction are barriers to
medication adherence.57,74
On the attitude towards medication, there is a positive attitude related
to adherent patients,48,52,64 and vice
versa.24 According to statistical differences between
adherent and nonadherent patients, adherent patients show a stronger
positive attitude than nonadherent patients.59 In
addition, low-level adherence to AD medication is associated with low
treatment satisfaction23, lack of
knowledge.24 On the other hand, adherence to
medications can be influenced by a negative emotional reaction to
regulations or recommendations of medication use that affect freedom and
autonomy, and beliefs regarding the control of health. Psychological
reactance and chance external locus of control have positive
associations and levels of adherence, where more reactant patients are
less adherent, also a negative relationship with an external locus of
control, where more adherence when patients depend on their
doctors.53
Patients who take AD medications
seen is a sign of not normal and effect on behavior and mental state, so
this self-stigma towards AD medications affect medication
adherence.74 Also, self-stigma over depression, denial
about their disorder, nonacceptance of the disorder considered the major
reason for noncontinuous AD medication.25,34,73 On the
other hand, the expression of patients that want to feel better and
experience severe depressive symptoms that motivate adherence to AD
medications. Srimongkon et al73 reported that patients
revealed that self-motivation and self-management have a positive impact
on adherence. Although, the insight of diagnosis may factor that
influence adherence.24,57 Moreover, patients revealed
that forgetfulness is a negative effect on medication
adherence.24,60 The patient’s personal obligations
such as traveling; carelessness; and confusion negatively influence AD
medication adherence.57,60