Assessment of Medication Adherence and Related Factors in Hypertensive Patients: The Role of Beliefs About Medicines

Abstract

Low medication adherence is one of the leading causes that affect the achievement of target levels for hypertension. Identifying modifiable factors associated with low adherence is crucial. This study aims to assess medication adherence and the role of beliefs about medicines on medication adherence among hypertensive patients.This cross-sectional study was conducted with 200 hypertension patients.Data were collected using the Morisky-Green-Levine Medication Adherence Scale, and the Beliefs about Medicines Questionnaire [BMQ-Turkish Translation (BMQ-T)]. It was found that the BMQ-T subscales of Specific Concern (β = 0.358, p = .027) and General Overuse (β = 0.552, p = .011) had an independent predictor effect on medication adherence scores. In this study, the patients who thought that drugs were overused and had concerns about this were seen to be less adherent with the medication. With regard to patients who use antihypertensive drugs but have uncontrolled blood pressure, their beliefs about drugs should not be ignored when evaluating adherence with drug therapy.

Keywords

antihypertensive drugs beliefs hypertension medication adherence

Introduction

Hypertension is defined as an elevation in systolic (≥140 mmHg) and/or diastolic (≥90 mmHg) blood pressure values measured under hospital conditions (Williams et al., 2018). Hypertension is an independent modifiable risk factor for cardiovascular diseases and affects many other health issues, such as strokes and kidney disease (Simons et al., 2018). The global prevalence of high blood pressure in adults aged 18 years and older is 31.1%, and its prevalence increases with age (Tibebu et al., 2017; Tilea et al., 2018). In the most recent PatenT2 study, the prevalence of hypertension in Turkey was reported to be 30.3%. According to this study, 54.7% of hypertensive patients were aware of their diagnosis, and the rate of treatment was 47.4%. The results of the PatenT2 study showed that hypertension remains a public health problem for our country as well as the world (Sengul et al., 2016).

When the results of the PatenT2 study were compared with the results of the PatenT study (Altun et al., 2005), a positive development was observed, as awareness, treatment rates, and treatment control of hypertension in recent years. However, awareness and treatment rates still seem to be insufficient. The studies on the factors affecting the achievement of target values for hypertension have shown that one of the leading causes is low medication adherence (Bosworth et al., 2006; Uludag et al., 2016). Medication adherence is generally defined as the extent to which patients take drugs as prescribed by their health care providers (Yue et al., 2015). Nonadherence to antihypertensive treatment affects 10 to 80% of hypertensive patients and is one of the key drivers of suboptimal blood pressure control (Unger et al., 2020).

Despite the relatively easy methods available for both diagnosis and treatment, the management of hypertension is still poor (Gozum & Hacihasanoglu, 2009), and a low adherence with treatment appears to be observed (Lewis, 2012; Vrijens et al., 2008). Nonadherence to antihypertensive drug therapy may increase the number of hypertensive attacks and lead to the damage of target organs, repeat hospitalizations, decrease in quality of life, and increase in healthcare costs and the risk of mortality (Lee et al., 2013; Tan et al., 2017; Zyoud et al., 2013). This is a growing concern for clinicians, health systems, and other stakeholders (e.g., payers) (Ho et al., 2009). Using the medication event monitoring (MEMS) data, Vrijens et al. (2008) reported that about half of the patients who were prescribed antihypertensive drugs stopped their treatment during the first year, and approximately 10% omitted their daily medication. In addition, directly observed therapy (DOT) approaches in recent years have clearly demonstrated that blood pressure is normalized in many patients when the treatment is given under controlled conditions (Eskås et al., 2016). This indicates that maintaining adherence to antihypertensive drugs is as important as starting the treatment.

Nonadherence behavior could conceptually be categorized into two subtypes: unintentional (due to forgetfulness, regimen complexity, or physical problems) and intentional (based on a patient’s decision to take no/less medication). In intentional nonadherence, patients seem to be performing a risk-benefit analysis that assesses the perceived risks and benefits of the treatment. This evaluation process can be influenced by the patient’s beliefs about medications, self-efficacy, and knowledge about the disease (van den Bemt et al., 2012). Recently, patients’ motivations for the treatment have been shown to possibly affect adherence (de Thurah et al., 2010). Many factors such as the demographical characteristics of the patients; side effects of the drugs; the suitability of the drug dose; cost and number of drugs; knowledge, beliefs, attitude, perceptions, and expectations about hypertension and treatment; patients’ participation in the care; health system problems; and treatment effectiveness play a role in compliance with antihypertensive treatment (Horne et al., 1999; Mostafavi et al., 2016; Tan et al., 2017).

It is necessary to point out the magnitude and scope of the problem and determine factors decreasing medication adherence to reach better rates of adherence (Wheeler et al., 2014). In the literature, the issue of adherence with antihypertensive treatment was frequently addressed, and both personal-based and disease-specific factors of the socio-demographic characteristics were emphasized. However, there are limited data to examine the level of patients’ beliefs about medicines in terms of adherence to the treatment. Beliefs about medicines may be a patient-related factor that predicts medication nonadherence. Therefore, this study aimed to assess medication adherence and the role of beliefs about medicines on medication adherence in hypertensive patients.

Method

Study Design, Sample, and Setting

The study was designed as cross-sectional research. It was conducted on participants with hypertension who applied to the cardiology and internal medicine outpatient clinics between February and December 2018.

The inclusion criteria were: (a) having a diagnosis of hypertension (according to the 2018 European Society of Cardiology [ESC]/European Society of Hypertension [ESH] Guidelines for the management of arterial hypertension (Williams et al., 2018); (b) using at least one antihypertensive drug for at least six months before the commencement of the study; (c) being 18 years or older; (d) being able to speak, read, and write in Turkish; and (e) providing consent to participate in the study. The exclusion criteria were: (i) being diagnosed with major psychiatric diseases; (ii) having cognitive impairment; (iii) having a concurrent terminal illness or being clinically unstable; and (iv) inability to give informed consent.

Ultimately, a total of 203 participants with hypertension were enrolled in the study. Of those, three participants were excluded from the analysis due to not completing the questionnaires. Consequently, the analysis was limited to the data of the remaining 200 participants.

Definition

According to ESC/ESR criteria, those with systolic blood pressure between 140 to 159 mmHg and/or diastolic blood pressure between 90 to 99 mmHg are classified as grade 1, those with systolic blood pressure between 160 to 179 mmHg and/or diastolic blood pressure 100 to 109 mmHg as grade 2, and those with systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥110 mmHg as grade 3 hypertension (Williams et al., 2018).

Data Collection and Procedure

The study was conducted in the cardiology and internal medicine outpatient clinics. The participants consisted of those who came to the polyclinic for routine control. Detailed clinical evaluations of the participants were made by specialist physicians. An interview was then held with the participants who voluntarily agreed to participate in the study, and informed consent was received by the researchers in the outpatient rooms. During this interview, the participants were informed about the forms. The participants were asked to fill out the questionnaires. This process took approximately 20 to 25 minutes.

The participant assessment form, Morisky-Green-Levine Medication Adherence Scale (MGLS), and Beliefs about Medicines Questionnaire (BMQ-Turkish Translation (BMQ-T) forms were used in this study.

Participant Assessment Form

This form was used to collect data on sociodemographic (age, gender, educational, marital and working status, cohabitation, socioeconomic situation, smoker) and clinical (duration of disease, drug-related adverse events, comorbidity, use of herbal remedies, salt-restricted diet, regular physical activity, blood pressure measurement, body mass index) characteristics of the participants.

Morisky-Green-Levine Medication Adherence Scale (MGLS)

This 4-item dichotomous scale was developed by Morisky et al. (1986) to determine the adherence of patients to medication regimens. The reliability and validity in Turkish were realized by Bahar et al. (2014). Each item asks patients whether they exhibit a specific type of nonadherent behavior. For each item, a yes or no response is assigned a score of 1 or 0, respectively. The score of the MGLS can range from 0 to 4, and higher scores indicate lower adherence to medication. In this study, participants are categorized into two groups according to their scores: 0 = adherent; 1,2,3,4 = nonadherent (Khanderia et al., 2008).

Beliefs About Medicines Questionnaire (BMQ)

This scale was validated for the Turkish population [BMQ-Turkish Translation (BMQ-T)] by Cinar et al. (2016) and is used to assess patients’ perceptions and expectations about medications. The original BMQ was developed by Horne et al. (1999). It consists of general and specific sections, with two subscales for each. The subscales of the BMQ-General section are General Harm and General Overuse, both consisting of four items. The General Harm subscale assesses patients’ beliefs about the degree to which drugs are perceived as essentially harmful, while the General Overuse subscale addresses views on how drugs are used by physicians. The BMQ-Specific consists of two subscales, Specific Necessity and Specific Concern, with five items each that assess patients’ beliefs about the necessity of prescribed medication for controlling their disease and their concerns about the potential adverse consequences of taking it. The higher scores of each section indicate stronger belief in the concept of that section.

Data Analysis

Statistical analyses were performed using the IBM Statistical Package for Social Sciences, Statistics for Windows, Version 24.0 (IBM Corp.; Armonk, NY, USA, Released 2016). Continuous variables were expressed as mean ± standard deviation (SD) (if normally distributed) or median [Interquartile Range (IQR) (Q1-Q3)], (if not normally distributed), and categorical variables were expressed as numbers and percentages. The compatibility of the continuous data with a normal distribution was examined using the Kolmogorov-Smirnov test. Pearson’s Chi-Square Test was used to compare categorical dependent and independent variables. While the data were not normally distributed, the Mann-Whitney U test was used to compare scores between two groups. For the data that were normally distributed, comparisons between the two groups were assessed using the Independent Samples T-test.

Multivariate Binary Logistic Regression Model was carried out using variables that showed significance in univariate analysis. A binary logistic regression model was used to calculate the odds of potential risk factors associated with medication nonadherence. Adherence status as defined by the MGLS was used as dependent variables. In the analysis, each independent variable was first included in the regression model, and then all the factors were combined together in the “Enter” method. In this method the analysis is made by handling all variables together. When the fit of the model was examined with the Hosmer-Lemeshow test, it was found to be an adequate model (χ² = 5.579, df = 8, p = .694). For all the analyses, a p-value of less than .05 was accepted to be statistically significant.

Ethical Considerations

This study was approved by the Institutional Review Board (IRB) of the university (Session No:2018/2). All study participants provided written informed consent in accordance with the principles of the Declaration of Helsinki. Participants were provided with information about the objective of the study, privacy, and confidentiality.

Results

According to the findings of the current study, 54.5% of the participants were adherent with the treatment. The mean age of the participants (38 male, 162 female) was 61.90 ± 10.84 years, and the median duration of hypertension was 10.0 years (IQR, 5.0–17.0). When the participants’ adherence to treatment and sociodemographic and clinical characteristics were compared, it was found that participants’ adherence to treatment significantly increased with increasing age and duration of hypertension (t = 3.024, p = .003; t = −2.742, p = .006, respectively). The treatment adherence status was not changed with any other variables (Table 1).

Table l.

Sociodemographic and Clinical Characteristics of the Participants.

Characteristics	All participants 200 (100.0)	Adherent 109 (54.5)	Nonadherent 91 (45.5)	Statistics	p-value
Age (years)^†	61.90 ± 10.84	63.98 ± 10.01	59.42 ± 11.32	3.024^a	.003
Gender^‡				0.383^b	.536
Female	162 (81.0)	90 (82.6)	72 (79.1)
Male	38 (19.0)	19 (17.4)	19 (20.9)
Educational status^‡				1.857^b	.603
Illiterate	21 (10.5)	10 (9.2)	11 (12.1)
Secondary	127 (63.5))	69 (63.3)	58 (63.7)
High school	26 (13.0)	13 (11.9)	13 (14.3)
University and over	26 (13.0)	17 (15.6)	9 (9.9)
Marital status^‡				0.508^b	.476
Married	140 (70.0)	74 (67.9)	66 (72.5)
Single	60 (30.0)	35 (32.1)	25 (27.5)
Working status^‡				0.467^b	.494
Employed	23 (11.5)	11 (10.1)	12 (13.2)
Unemployed/retired	177 (88.5)	98 (89.9)	79 (86.8)
Cohabitation^‡				3.248^b	.517
Living alone	28 (14.0)	16 (14.7)	12 (13.2)
Living with a partner and children	73 (36.5)	34 (31.2)	39 (42.9)
Living with a partner	69 (34.5)	42 (38.5)	27 (29.7)
Living with a children	24 (12.0)	14 (12.8)	10 (11.0)
Living with relatives	6 (3.0)	6 (2.8)	3 (3.3)
Socioeconomic situation^‡				1.074^b	.584
Less income than expenditures	78 (39.0)	39 (35.8)	39 (42.9)
Income equals expenditures	112 (56.0)	64 (58.7)	48 (52.7)
More income than expenditures	10 (5.0)	6 (5.5)	4 (4.4)
Smoker^‡				1.239^b	.266
Yes	56 (28.0)	27 (24.8)	29 (31.9)
No	144 (72.0)	82 (75.2)	62 (68.1)
Duration of hypertension (year)^§	10.0 (5.0-17.0)	11.0 (5.5-20.0)	10.0 (4.0-15.0)	−2.742^c	.006
Experiencing drug-related adverse events^‡				1.703^b	.192
Yes	30 (15.0)	13 (12.0)	17 (18.7)
No	170 (85.0)	95 (88.0)	74 (81.3)
Comorbidity^‡				0.610^b	.435
Yes	160 (80.0)	85 (78.0)	75 (82.4)
No	40 (20.0)	24 (22.0)	16 (17.6)
Using herbal remedies^‡				0.011^b	.916
Yes	38 (19.0)	21 (19.3)	17 (18.7)
No	162 (81.0)	88 (80.7)	74 (81.3)
Salt-restricted diet (self-reported)^‡				3.093^b	.079
Yes	121 (60.5)	72 (66.1)	49 (53.8)
No	79 (39.5)	37 (54.5)	42 (46.2)
Regular physical activity (self-reported)^‡				3.033^b	.082
Yes	70 (35.0)	44 (40.4)	26 (28.6)
No	130 (65.0)	65 (59.6)	65 (71.4)
Blood pressure measurement^‡				1.276^b	.259
Yes	58 (29.0)	28 (25.7)	30 (33.0)
No	142 (71.0)	81 (74.3)	61 (67.0)
BMI (kg/m²)^§	30.9 (27.1–34.0)	30.9 (26.6–33.9)	31.1 (27.7–34.3)	−.979^c	.328

Note. BMI = body mass index.

Independent Samples t test.

Pearson Chi-Square test.

Mann Whitney U test.

†

Mean ± SD.

‡

n (%).

Median (Q1–Q3).

In terms of comparing BMQ-T scores and treatment adherence, it was found that Specific Concern, General Overuse, and General Harm scores were higher in nonadherent participants (p < .05) [Median (Q1–Q3): 2.6 (1.8–3.4) vs. 1.6 (1.0–2.6), 3.0 (2.5–4.0) versus 3.0 (2.3–3.3), 2.8 (2.0–3.8) versus 2.0 (1.5–3.0) respectively]. Conversely, there was no significant relation between Specific Necessity scores and treatment adherence (p = .383) (Table 2).

Table 2.

Comparison of the Medication Adherence Status of Participants and the Beliefs About Medicines Questionnaire Scores (n = 200).

Variable	All participants	Adherent	Nonadherent	Z	p-value
Variable	Median (Q1–Q3)	Median (Q1–Q3)	Median (Q1–Q3)	Z	p-value
BMQ-T-Specific Necessity	4.2 (3.2–4.8)	4.2 (3.4–4.8)	4.2 (2.8–5.0)	−0.872	.383
BMQ-T-Specific Concerns	1.8 (1.0–2.9)	1.6 (1.0–2.6)	2.6 (1.8–3.4)	−0.605	<.001
BMQ-T-General Overuse	3.0 (2.5–3.5)	3.0 (2.3–3.3)	3.0 (2.5–4.0)	−0.443	.001
BMQ-T-General Harm	2.3 (1.8–3.3)	2.0 (1.5–3.0)	2.8 (2.0–3.8)	−0.363	.001

Note. Z = Mann Whitney U test.

The results of the multivariate analysis that were significantly associated with medication nonadherence of the participants are shown in Table 3. Hypertension patients with high concerns (BMQ-T-Specific Concern) about adverse consequences of hypertension medications and those with high beliefs that medicines are overused (BMQ-T-General Overuse) were more likely to be nonadherent [(O.R = 1.43; 95% C.I of 1.04–1.96) and (O.R = 1.74, 95% C.I of 1.13–2.67) respectively].

Table 3.

Multivariate Analysis of Risk Factors Associated with Medication Nonadherence.

Covariate	β	S.E.	Wald	Odds ratio^†	p-value	95% C.I
BMQ-T-Specific Concern	0.36	0.16	4.88	1.43	.027	1.04–1.96
BMQ-T-General Overuse	0.55	0.22	6.39	1.74	.011	1.13–2.67

Note. C.I = confidence interval; β = coefficient of predictor variables; S.E. = Standard error.

†

Enter method was used.

Discussion

Hypertension is a chronic disease that causes serious complications in terms of uncontrolled blood pressure. Management of hypertension consists of two essential parts: pharmacological treatment and lifestyle changes. Nonadherence with drug therapy is an important factor that prevents blood pressure control in more than two-thirds of hypertensive individuals (Tibebu et al., 2017). Therefore, determining the factors related to treatment adherence is vital. The current study aimed to assess medication adherence and the role of beliefs about medicines on medication adherence in hypertensive patients.

In this study, it was found that as age and duration of hypertension increased, patients’ adherence with treatment significantly increased. In addition, Specific Concern, General Harm, and General Overuse subscale scores of BMQ-T were found to be significantly higher in nonadherent patients. In the regression analysis, Specific Concern and General Overuse scores of BMQ-T were found to be the most highly related items with medication adherence. Therefore, according to the findings of the current study, the Specific Concern and General Overuse about medication are significant predictors of medication nonadherence in hypertensive patients. There are studies showing that negative beliefs about medications are a strong barrier to successful adherence (Chummun & Boland, 2013; Gatti et al., 2009; Sirey et al., 2013; Sweileh et al., 2014). Therefore, healthcare professionals, especially nurses, should consider patients’ beliefs about medications in order to improve medication adherence.

The causes of nonadherence can be characterized as unintentional and intentional. According to the unintentional reasons for nonadherence, the patient wants to receive the treatment but cannot due to limitations in their capacities and resources (e.g., forgetfulness, poor understanding, lack of funds). In the current study, sociodemographic factors, such as socioeconomic and working status, did not have an effect on patients’ adherence to treatment.

Intentional nonadherence can be defined as the patient deciding not to take the drug as recommended. Preferences and beliefs may be factors related to nonadherence to treatment in intentional nonadherence (Horne et al., 2009). In the current study, high Specific Concern and General Overuse scores were the most influential factors in nonadherence to treatment. In recent studies on various chronic conditions, nonadherence has been demonstrated to be related to doubts about the need for personal treatment and concerns about potential negative effects (Horne et al., 2009). Patients with stronger concerns about prescribed medication may be more skeptical; they may search for more information about their treatment options and be assertive to change their current treatment. In the current study, patients who thought that the drugs were overused by the doctors and believed that the drugs were “harmful,” “addictive,” and “poison” displayed low adherence to treatment. Generally, patients who believe that drugs are harmful to them believed that not taking these drugs was a better option. In addition, these patients tend to be concerned about the potential side effects of the drugs (Horne et al., 1999). Similarly, according to this study, it can be said that patients who thought that drugs are overused (General Overuse) and had concerns about drugs (Specific Concern) had low adherence levels to avoid the potential side effects of the drugs. In the BMQ-T Specific Concern subscale, it was observed that the participants expressed their concerns mostly by marking the “I sometimes worry about the long-term effects of my medicines” and “I sometimes worry about becoming too dependent on my medicines” items. In the General Overuse subscale, they mostly expressed their thoughts about overuse of medications with the items “If doctors had more time with patients they would prescribe fewer medicines” and “Doctors place too much trust on medicines.”

Several studies have shown that a lower rate of adherence to treatment can be seen in patients with stronger beliefs about Specific Concern, particularly in patients with heart failure (Dias et al., 2014), chronic diseases (Sirey et al., 2013), and hypertension (Al-Noumani et al., 2018; Ruppar et al., 2012). In the studies by Al-Noumani et al. (2018) and Ruppar et al. (2012), higher medication adherence was reported among patients with stronger beliefs about medication necessity and fewer concerns about medication. The medication adherence results from a balance between the perception of the need to take medication and concerns about their adverse effects (Dias et al., 2014). However, in this study, considering the results of the regression analysis of parameters that found to be significantly associated with medication adherence, only the Specific Concern and General Overuse emerged as an important indicator of adherence to treatment. The lower the patients’ beliefs about the concerns and overuse, the greater is the adherence to medicines.

Similar to current study, Ivarsson et al. (2018) found that there was no difference between medication adherence and patients’ beliefs about the necessity of the medications, but concerns about the potential side effects of taking the medication were significantly related to adherence. However, this study was conducted using only the specific part of the BMQ. Considering the results of the studies, concerns about the long-term effects of taking hypertension medications should be handled by nurses in order to reduce concerns and ultimately increase medication adherence. For example, patients should be informed that there may be seen electrolyte disturbances in diuretic users, fatigue, dizziness and weakness in beta blocker users, and skin rash, chronic dry cough and kidney damage in those using angiotensin converting enzyme inhibitor.

However, some studies do not support the finding that beliefs about medicines are an important factor in medication adherence. For instance, Hedenrud et al. (2008) reported that approximately one-third of migraine patients do not adhere to their prophylactic medication, and beliefs in drugs and drug-related factors cannot predict discordance among these patients. Similarly, in a study conducted in persistent hypertension patients, it was found that beliefs about medicines did not predict adherence (Durand et al., 2018). From these findings, we can say that the effect of beliefs on medication adherence depends on the kind of the chronic disease.

According to recent studies, it has been determined that almost half of the hypertensive patients did not attend to their control visits, and a rate of 30 to 50% fail to use antihypertensive drugs (Vatansever & Ünsar, 2014). In the current study, the medication adherence rate was found to be 54.5%, and almost half of the patients did not take their medication regularly. Similarly, the adherence rate was reported as 57% in Ivarsson et al. (2018) and 51.7% in Yue et al. (2015). However, it should not be overlooked that these medication adherence studies were carried out with different methods (electronic pill count, self-reported, etc.). In the study by Tibebu et al. (2017), the adherence rate to treatment was found to be 66.8%. It was stated that middle-aged and older adults were more compliant than young adults, and those with sufficient knowledge about the disease displayed more adherence than those without knowledge. In the current study, although Specific Concern and General Overuse were found as the most influential factors in the treatment belief subscales, the age of the patient and the length of the disease duration increased were also positively associated to adherence to medication.

Medication adherence and continuity are significantly affected by the psychosocial and behavioral characteristics of the patient. These may include a sense of insecurity to drugs or negative beliefs about medications. While some factors influencing nonadherence cannot be changed, certain psychosocial and behavioral traits may change with education, good communication, and support (Wheeler et al., 2014). For this reason, it is important to know which factors affect medication adherence in order to provide the most optimal control of hypertension among antihypertensive drug users. Improving medication adherence in patients with poor control of blood pressure is a crucial role for nurses and healthcare providers. It is necessary to determine the main problem of the patient, what should be done, and why it is important to do so. In addition, it is necessary to have the conversations with the patients so that they understand why the treatment will be beneficial. For example, consider a patient who believes that “regular medication will be harmful” when there is normal blood pressure under medication. It is important to inform this patient that sudden changes in blood pressure may occur as a result of irregular drug use and this may cause serious end organ damage. Depending on whether their beliefs are right or wrong, they will have a positive or negative effect on medication adherence. Therefore, medication adherence can be increased by changing beliefs in the right direction with education.

Limitations

The most important limitation of this study was the use of questionnaires based on patient self-reports. Therefore, misunderstanding or misinterpretation of the questions might have affected the results of the study. Although this study provides a valuable contribution to the understanding of nonadherence with hypertension drugs, it was conducted in only one research hospital and has a modest sample size.

Relevance to Clinical Practice

The results of this study are important in terms of showing how medication adherence in patients with hypertension is influenced by beliefs about medicines, age, and duration of hypertension. Although beliefs can change, sociodemographic and clinical factors cannot be altered to a great extent. Concerning patients who use antihypertensive medication but have uncontrolled blood pressure, we recommend evaluating the patients’ beliefs about medicines while evaluating adherence with drug treatment and the factors related to it. Identifying patients’ concerns as part of patient-centered education and support will help to increase adherence to medications. Given the results of the study, nurses may have an important role in minimizing patients’ concerns about drugs and ultimately improving medication adherence. For this purpose, patients should be informed that their hypertension medicines are not addictive and have an acceptable safety profile for long-term use.

Conclusion

The current study showed that stronger concerns about the potential side effects of the medication and beliefs about overuse by physicians could negatively affect patients’ adherence to antihypertensive medication. With regard to patients who use antihypertensive drugs but have uncontrolled blood pressure, their beliefs about drugs should not be ignored when evaluating the adherence with drug therapy.

Footnotes

Acknowledgements

We thank the patients for taking the time to fill in the questionnaires and for contributing to the study.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iDs

Fatma Ilknur Cinar

Bilge Bal Özkaptan

Author Biographies

Fatma Ilknur Cinar, RN, PhD, is associate professor in Gülhane Faculty of Nursing at University of Health Sciences Turkey. She is the head of the Department of Internal Medicine Nursing.

Şule Mumcu, RN, is research assistant in Bingol University, Faculty of Health Sciences, Turkey.

Betülay Kiliç, RN, PhD, is assistant professor in Gülhane Faculty of Nursing at University of Health Sciences Turkey.

Ülkü Polat, RN, PhD, is associate professor at Gazi University Faculty of Health Sciences, Ankara, Turkey. She is the head of the Department of Internal Medicine Nursing.

Bilge Bal Özkaptan, RN, PhD, is assistant professor in Department of Nursing at Sinop University Faculty of Health Sciences, Turkey.

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