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