International Journal of Hypertension
Volume 2020 (2020), Article ID 9540810, 10 pages
https://doi.org/10.1155/2020/9540810

Research Article

Adherence to Antihypertensive Treatment and Associated Factors in Central Ethiopia

Daniel G/Tsadik,¹ Yemane Berhane,² and Alemayehu Worku³

¹Department of Nursing, School of Health Sciences, Arsi University, Asella, Ethiopia
²Addis Continental Institute of Public Health, Addis Ababa, Ethiopia
³School of Public Health, Addis Ababa University, Addis Ababa, Ethiopia

Correspondence should be addressed to Daniel G/Tsadik; danielt@arsiun.edu.et

Received 25 April 2020; Revised 28 September 2020; Accepted 8 October 2020; Published 23 October 2020

Academic Editor: Tomohiro Katsuya

Copyright © 2020 Daniel G/Tsadik et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract.

Background. Adherence to treatment is a primary determinant of treatment success. Nonadherence attenuates clinical benefits to the recipients of the treatment. However, monitoring adherence to long treatment regimens is not given due emphasis in low-income contexts. This study aimed to assess adherence to antihypertensive treatment and factors associated with it in Central Ethiopia. Method. This is an institution-based cross-sectional study conducted in 4 public hospitals in Central Ethiopia from December 4, 2016, to September 25, 2017. The Morisky Medication Adherence Scale (MMAS-8) was used to assess the level of adherence. The Revised Illness Perception Questionnaire (IPQ-R) was used to assess illness perception. The MMAS-8 score ranges from 0 to 8, a score of 8 reflects high adherence, 6 to 7 medium adherence, and <6 low adherence. Results. A total of 989 hypertensive patients participated in the study, of which 36.0% were assessed to have high adherence, 31.7% medium adherence, and 32.3% low adherence. We found that treatment adherence was significantly and positively associated with having family support (AOR: 1.65; 95% CI = 1.23, 2.22), high perception about consequences of hypertension (AOR: 1.51; 95% CI = 1.17, 1.95), and high perception about the severity of the disease (AOR: 1.42; 95% CI = 1.09, 1.86). Conclusion. The treatment adherence to antihypertensive medications is low in Central Ethiopia. Engaging family members in the treatment plan and improving patients’ understanding of the illness are critical in achieving high adherence to medication in this context.

1. Introduction

Hypertension (HTN) is one of the major public health problems globally [1, 2], in both high-income as well as low- and middle-income countries [3]. However, awareness about the disease and its prevention and treatment are low in low- and middle-income countries compared to developed countries [3]. According to the Global Burden of Disease Study, hypertensive heart disease accounts for 17.5 million disability-adjusted life years in 2015 [4]. Optimal control of blood pressure is paramount to prevent hypertension-related complications and deaths [5]. High adherence to antihypertensive medications can effectively lower hypertension-related complications and improve survival [6, 7].

Medication adherence is defined as “the extent to which the medication-taking behavior of a patient corresponds with agreed recommendations/prescriptions.” Patients receiving medication need to understand that the medications are critical to achieving blood pressure control [8, 9]. Many studies have suggested that a high level of adherence to antihypertensive drug treatment is related to better blood pressure (BP) control and a reduced risk of cardiovascular disease (CVD) [8, 10–13]; however, low adherence to antihypertensive drugs is a major public health and clinical challenges in the treatment of hypertension in low- and middle-income countries [14, 15]. Patients who poorly adhere to antihypertensive medications have a higher risk of adverse outcomes, including hospitalization, and incur higher healthcare costs due to complications as compared to patients who had good adherence [12, 13, 16, 17].

Multiple factors including patients’ beliefs about health, illness, and treatment contribute to antihypertensive medication adherence therapy [18–23]. In treating hypertension, understanding patient’s beliefs about medication adherence is fundamental because hypertension is silent and asymptomatic. Thus, patients might have misperceptions about hypertension, its severity, and the significance of its management [24, 25]. Socioeconomic status (poverty), low level of education, unemployment, lack of effective family/social support, and forgetfulness are also associated with adherence [26]. The patients’ illness representations also have a direct influence on adherence to treatment [27].

Although the importance of treatment adherence has been recognized in Ethiopia by prior studies, the previous studies were conducted on a small number of patients often drawn from a single hospital and gave emphasis mostly only to sociodemographic factors [28–32]. Important independent factors that could influence patients’ adherence to their treatment such as illness perception and health belief were hardly studied in Ethiopia. Hence, this study assessed the magnitude of antihypertensive treatment adherence and factors associated with it in multiple hospitals in Central Ethiopia.

2. Material and Methods

2.1. Study Design and Setting

This is a hospital-based cross-sectional study conducted from December 4, 2016, to September 25, 2017. The study was conducted in 4 public hospitals, namely, Bishoftu, Adama, Asella, and Shashemene. These hospitals are located in Oromia Regional State in Central Ethiopia. The hospitals provide a comprehensive healthcare service for both outpatient and inpatient clients. These hospitals also have specialty clinics where patients with specific chronic diseases are referred for follow-up. The hypertension clinic is one of those clinics. In Ethiopia, prescriptions are written by a physician in the follow-up clinics and patients get their medications from pharmacies from the same facility or pharmacies outside the healthcare facilities.

2.2. Study Population

All adults following their antihypertensive treatment in the four study hospitals were and who fulfilled the inclusion criteria were included in the study. The inclusion criteria include age at least 18 years or above, a diagnosis of hypertension confirmed by a physician, patients on antihypertensive medication for at least 3 months, patients who can give consent to participate in the study, and patients with no acute distress related to any disease during recruitment of study participants. Pregnant women, patients who cannot give consent, and patients who have hearing and/or speaking problems were excluded from the study.

2.3. Sample Size and Sampling Procedures

The sample size for determining the proportion of adherence to hypertensive treatment was determined with the following assumption: adherence to antihypertension treatment taken as 64.6% based on Ambaw et al. study [28], a 4% precision, 95% level of confidence, and 10% nonresponse rate. Accordingly, the calculated sample size was 604. For factors associated with adherence to antihypertensive treatment, we used a research conducted by [28]. Using StatCalc, the most determinant factor for treatment adherence was residence of the patients and considering , OR = 0.64, 80% power, 95% confidence level, and 1 : 1 (n₁ = n₂) ratio. After adding 10% nonresponse, the calculated sample size was 1030 (515 urban and 515 rural). Hypertensive patients who consented for the study were consecutively enrolled until the required sample was fulfilled.

2.4. Data Collection

Data were collected using a uniform and pretested questionnaire by 12 trained nurses (3 for each hospital). The study nurses were not working at the hypertension clinic. Data were collected through a face-to-face interview. The data collectors were competent to do interviews either in Amharic (the national language) and Afaan Oromo (the state language). Additionally, one nurse was assigned to supervise the data collection process at each hospital. Patients were interviewed after they got their routine services at existing. Before collecting data, the data collectors explained the objective of the study and obtained informed verbal consent from each study participant. The data collection tool contained questions on sociodemographic information, lifestyle, health-related matters, illness perception (IPQ-R) [33], the Morisky Medication Adherence Scale (MMAS-8) [34], and health beliefs. Some of these components are described in more detail below.

2.5. Illness Perception Questionnaire-Revised (IPQ-R)

The Illness Representation (IR) component of the validated IPQ-R [33] had seven subscales and 34 questions including the subdimensions of the timeline, timeline cyclical or symptoms fluctuate over time, consequences, personal control, treatment control, illness coherence, and emotional representations. In all dimension’s subjects were given 5 options which were converted to a 5-point Likert-type scale for result analysis: strongly disagree (1), disagree (2), neither agree nor disagree (3), agree (4), and strongly agree (5).

For all these subscales, partial scores were defined as the mean of the scores for the items on each subscale (considering direct and inverse items, eight negative item scores were reversed: 1, 6, 13, 15, 19, 22, 23, and 32). Then, responses of all items are summed according to the IR dimensions (4 items of the timeline, 4 items of timeline cyclical, 6 items of consequences, 4 items of personal control, 5 items of treatment control, 5 items of illness coherence, and 6 items of emotional perceptions) and then dichotomized in to high and low by their mean. A higher score indicates stronger beliefs about the disease chronicity, cyclical course, impact and outcomes, personal influence, cure possibilities, perceived understanding, and emotional reactions to the disease. The internal consistency of Cronbach’s alpha of the IPQ-R was checked and was 0.78, indicating satisfactory internal consistency.

2.6. Hypertension Belief and Behavior Questionnaire

The questionnaire is generated by referring to previously published studies based on the constructs of the HBM [35]. The HBM consisted of perceived susceptibility, perceived severity, perceived benefits, perceived barriers, perceived self-efficacy, and cues to action. The scores of each one of the HBM constructs were evaluated based on a 5-item Likert scale. Perceived susceptibility, perceived severity, perceived benefits, perceived barriers, perceived self-efficacy, and cues to action consisted of 4, 5, 5, 5, 4, and 4 questions, respectively.

2.7. Adherence to Medication

Medication adherence was measured using a validated eight-item self-reported Morisky Medication Adherence Scale (MMAS-8) [34]. Each item measures specific medication-taking behavior. Approval was obtained from professor Morisky to use his scale. The questions are phrased to avoid the “yes-saying” bias by reversing the wording of the questions about the way patients might experience failure in following their medication regimen since there is a tendency for patients to give their physicians or other healthcare providers positive answers [34].

This scale is a questionnaire with high reliability and validity, which has been particularly useful in chronic conditions such as hypertension. Response choices were “Yes” or “No” for items 1 through 7, and item 8 has a four-point Likert response scale. Total scores on the MMAS-8 ranged from 0 to 8, with scores of 8 reflecting high adherence, 6 to <8 reflecting medium adherence, and <6 reflecting low adherence. The internal consistency of Cronbach’s alpha of the MMAS was checked and was 0.72 [34, 36, 37].

2.8. Statistical Analyses

Descriptive statistics were used to summarize sociodemographic, disease characteristics of the study population, and the nature and frequency of antihypertensive medications used. We examined sociodemographic, health-related variables, illness representation variables, and health belief items considering adherence as an outcome variable. The variables which have a . value of 0.25 in bivariate analysis entered into multivariable ordinal logistic regression analysis. The ordinal logistic regression model was used because the outcome variable had three ordered levels of adherence (low⁄ medium/high). This model compared adjacent levels: the odds ratio (OR) corresponded with the odds of adherence to the next lower level. The ORs are presented with their 95% confidence intervals (CIs). The level of significance was set at a value of less than 0.05. STATA 12 software was used for data entry and analyses.

3. Result

A total of 989 study participants were interviewed from four public hospitals in Central Ethiopia. The response rate was 96.0%. The mean age of respondents was 57.6 years (SD = 11.8). Orthodox Christians and the Oromo ethnic group accounted for 64.6% and 51% of the respondents, respectively. More than three-fourth (76.8%) of the respondents were urban residents. Six hundred twenty-seven (63.4%) reported to be married, 34.6% were illiterate, and 32.9% were housewives (Table 1).

Table 1: Sociodemographic characteristics of hypertensive patients in Central Ethiopia, 2017 (n = 989).

Variable
Frequency
%

Sex

    Male
468
47.3

    Female
521
52.7

Name of the hospital

    Asella
322
32.5

    Adama
268
27.1

    Bishoftu
246
24.9

    Shashemen
153
15.5

Age

    20–35
43
4.3

    35–49
241
24.4

    50–64
512
51.8

    65–79
193
19.5

    Mean and SD (57.6 ± 11.8)

Religion

    Orthodox
639
64.6

    Muslim
221
22.4

    Protestant
129
13.0

Address

    Urban
760
76.8

    Rural
229
23.2

Level of education

    Illiterate
342
34.6

    Read and write
148
14.9

    Primary
177
17.9

    Secondary
172
17.4

    Diploma and above
150
15.2

Marital status

    Single
154
15.6

    Married
627
63.4

    Divorced
55
5.5

    Widowed
153
15.5

Ethnicity

    Oromo
504
50.9

    Amhara
377
38.1

    Tigre
26
2.6

    Gurage
52
5.3

    Others
30
3.1

Occupation

    GOV employed
154
15.6

    Self-employed
151
15.3

    Farmer
129
13.0

    Housewife
325
32.9

    Retired
230
23.2

About three-fourth (73.8%) of the respondents reported that it takes half an hour or more for a single trip to reach the hospital where they are receiving antihypertensive treatment. More than half (55.7%) of the respondents visit the hospital once every month; about three-fourth (72.7%) did not have a family history of hypertension, and the majority (79.1%) reported getting support from their family or friends (Table 2).

Table 2: Health-seeking and illness-related factors of hypertensive patients in Central Ethiopia, 2017 (n = 989).

Variable
Frequency
%

Frequency of visit

    Once or less per month
633
64.0

    Once in 2 months or more
356
36.0

Distance of residence

    ≤30 minutes
259
26.19

    >30 minutes to <1 hour
379
38.32

    ≥1 hour
351
35.49

Family history of hypertension

    Yes
234
23.7

    No
755
76.3

Presence of family support

    Yes
782
79.1

    No
207
20.9

Concerning health-related conditions of the respondents, 42.8% were on treatment for about one to five years, 51.3% took two drugs daily, and about half (51.8%) took their drugs more than once per day. Three-fourth (75.1%) of the respondents reported no side effects of medications, 70.7% reported never heard about the side effects of the drug from healthcare providers, only 38.2% reported the cost of the drug is high, and the rest reported either fair or low. About half (52.9%) of the respondents had comorbid chronic illnesses, and the most frequently reported comorbidity was diabetes mellitus by 80.1% (n = 523). More than three-forth (81.3%) of the respondents sleep for more than 6 hours with an average of 6.95 hours (SD = 1.98). The mean values of systolic blood pressure were 139.56 (SD = 15.9) mmHg and 86.3 (SD = 8.32) mmHg for diastolic blood pressure (Table 3).

Table 3: Health-related conditions of hypertensive patients in Central Ethiopia, 2017 (n = 989).

Variable
Frequency
%

Duration on antihypertensive treatment

    <5 years
538
54.4

    ≥5 years
451
45.6

Number of antihypertensive drugs taken

    One
429
43.4

    More than one
560
56.6

Antihypertensive drugs dosage/frequency

    Once per day
477
48.2

    More than once
512
51.8

Any history of side effect to antihypertensive drugs

    Yes
246
24.9

    No
743
75.1

Ever told about the side effect of antihypertensive drugs

    Yes
290
29.3

    No
699
70.7

Perceived cost of the antihypertensive drugs

    Low
113
11.4

    Fair
498
50.4

    High
378
38.2

Anything that makes you stressed

    Yes
523
52.9

    No
466
47.1

Duration of sleep in an hour

    <4 hours
55
5.5

    4 to 8 hours
787
79.6

    >8 hours
147
14.9

Level of BP

    Controlled
415
41.9

    Uncontrolled
574
58.1

Concerning the respondent’s illness representation, the mean scores of the seven dimensions of illness representation were 13.2 ± 1.6 for timeline, 13.2 ± 2.2 for coherence, 13.1 ± 1.9 for controllability-personal, 14.5 ± 2.6 for controllability-treatment, 20.4 ± 2.8 for a consequence, 11.1 ± 3.1 for timeline cyclical, and 17.9 ± 4.3 for emotional representation, respectively. This information indicates that patients believed that hypertension tended to be relatively chronic, predictable, and controllable through personal effort or by medical treatment and that hypertension had relatively little influence on their lives. Patients also believed that they had a relatively good understanding of their hypertension and rarely felt negative emotions due to hypertension (Table 4).

Table 4: Illness perception of hypertensive patients in Central Ethiopia, 2017 (n = 989).

Variable
Frequency
%

Timeline acute/chronic

    Low
469
47.4

    High
520
52.6

Consequence

    Low
460
45.5

    High
529
53.5

Treatment control

    Low
428
43.28

    High
561
56.72

Personal control

    Low
422
43.3

    High
567
56.7

Illness coherence

    Low
544
55.1

    High
445
44.9

Timeline cyclical

    Low
495
50.1

    High
494
49.9

Emotional representation

    Low
523
52.9

    High
466
47.1

Illness representation

    Low
483
48.8

    High
506
51.2

In this study, the researcher tried to assess hypertensive patient’s beliefs using the health belief constructs. The findings indicated that respondents had lower beliefs of risk to contracting an illness or its complications (perceived susceptibility), lower beliefs that potential factors might make it difficult to take the behavior (perceived barriers), and lower internal or external cues that prompt the action, whereas they had higher beliefs that the disease is severe and has serious consequences (perceived severity), higher beliefs that taking treatment is beneficial to reduce or prevent disease threat (perceived benefit), and relatively good confidence to tackle their illness (self-efficacy) (Table 5).

Table 5: Hypertension belief and behavior of patients in Central Ethiopia, 2017 (n = 989).

Variable
Frequency
%

Perceived susceptibility

    Lower
588
59.5

    Higher
401
40.5

Perceived severity

    Lower
339
34.3

    Higher
650
65.7

Perceived benefits

    Lower
226
22.9

    Higher
763
77.2

Perceived barriers

    Lower
518
52.4

    Higher
471
47.6

Cues to action

    Lower
563
56.9

    Higher
426
43.1

Self-efficacy

    Lower
478
48.3

    Higher
511
51.7

Considering the frequency distribution of the MMAS-8 items, the majority or more than three-fourth of the respondents reported positive responses for MMAS-8 items. However, MMAS-8 items sometimes forget taking their drugs and having some degree of remembering problem to take their medications reported less than three-fourth of the respondents, 63.3% and 52.3%, respectively (Table 6).

Table 6: Responses of hypertensive patients to MMAS-8 questions in Central Ethiopia, 2017 (n = 989).

Variable
Frequency
%

Sometimes forget taking their drugs

    Yes
363
36.7

    No
626
63.3

Had a problem taking in the last 2 weeks

    Yes
164
16.6

    No
825
83.4

Stop taking or decrease the dose

    Yes
130
13.1

    No
859
86.9

Forget to bring along when traveling

    Yes
210
21.2

    No
779
78.8

Took their medication yesterday

    Yes
807
81.6

    No
182
18.4

Stop taking when they feel controlled

    Yes
149
15.1

    No
840
84.9

Felt hassled sticking treatment plan

    Yes
156
15.8

    No
833
84.1

Some degree of remembering a problem

    Almost never
517
52.3

    Sometimes
408
41.2

    Frequently
56
5.7

    Always
8
0.8

Use of the ©MMAS is protected by US copyright and registered trademark laws. Permission for use is required. A license agreement is available from MMAR, LLC., Donald E. Morisky, 294 Lindura Court, Las Vegas, NV 89138-4632, dmorisky@gmail.com.

Overall, 32.3% (95% CI: 29.1, 35.0) of participants demonstrated low adherence, 31.7% (95% CI: 29.0, 34.7) medium adherence, and 36.0% (95% CI: 33.0, 38.9) high adherence. About two-third (67.7%) (95% CI: 64.7, 70.7) of participants were either moderate or high adherent for their antihypertensive medications removed (Figure 1).

Figure 1: Hypertensive patient’s level of treatment adherence in Central Ethiopia, 2017.

In bivariate regression analysis, sex, educational status, occupation, frequency of visit, family support, perception on a timeline, perception on a consequence, cyclical perception, perceived susceptibility, perceived benefit, perceived severity, and cues to action had a significant association with treatment adherence.

After controlling possible confounding effects of other covariates, six factors remained as significant independent predictors of treatment adherence in the adjusted ordinal logistic regression model. These are farmer (AOR: 0.51; 95% CI = 0.33, 0.79), family support (AOR: 1.6; 95% CI = 1.23, 2.22), perceived consequences of hypertension (AOR: 1.51; 95% CI = 1.17, 1.95), perceived cyclical nature of hypertension (AOR: 0.76; 95% CI = 0.58, 0.95), perceived susceptibility (AOR: 0.61; 95% CI = 0.48, 0.78), and perceived severity of the disease (AOR: 1.42; 95% CI = 1.09, 1.86) had significant association with treatment adherence (Table 7).

Table 7: Effect of selected variable and other characteristics on adherence to antihypertensive treatment in Central Ethiopia, 2017.

Variable
Treatment adherence
COR (95% CI)
AOR (95% CI)
value

Low
Medium
High

Sex

    Male
166
144
158
1
1

    Female
153
170
198
1.26 (0.99, 1.58)
1.21 (0.94, 1.55)
0.133

Educational status

    Illiterate
98
113
131
1.57 (1.10, 2.24)
1.39 (0.94, 2.06)
0.103

    Read and write
52
42
148
1.31 (0.86, 1.99)
1.30 (0.83, 2.03)
0.245

    Primary
55
56
177
1.46 (0.97, 2.18)
1.28 (0.83, 1.95)
0.261

    Secondary
54
57
172
1.39 (0.93, 2.08)
1.26 (0.82, 1.92)
0.290

    Diploma and above
60
46
150
1
1

Occupation

    Gov. employed
46
38
70
1
1

    Self-employed
44
44
63
0.92 (0.60, 1.40)
0.86 (0.56, 1.32)
0.481

    Farmer
54
41
34
0.49 (0.32, 0.76)
0.51 (0.33, 0.79)
0.003

    House wife
108
108
109
0.69 (0.49, 0.99)
0.71 (0.49, 1.02)
0.068

    Retired
67
83
80
0.78 (0.53, 1.14)
0.70 (0.48, 1.05)
0.084

Frequency of visit

    Once in a month
159
180
212
1
1

    >Once in month
27
25
30
1.74 (1.03, 1.76)
1.04 (0.67, 1.61)
0.856

    Once in 2 months
42
17
33
1.17 (0.75, 1.86)
0.73 (0.47, 1.14)
0.164

    Once in 3 months or more
91
92
81
0.85 (0.54, 1.34)
0.92 (0.69, 1.22)
0.565

Family support

    Yes
235
252
295
1.52 (1.14, 2.02)
1.65 (1.23, 2.22)
0.001

    No
84
62
61
1
1

Treatment control

    Lower
141
148
133
1
1

    Higher
178
166
233
0.81 (0.63, 1.02)
0.86 (0.67, 1.11)
0.246

Perceived consequence

    Lower
162
156
142
1
1

    Higher
157
158
214
1.18 (1.17, 1.88)
1.51 (1.17, 1.95)
0.001

Cyclical perception

    Lower
162
173
209
1
1

    Higher
157
141
147
0.77 (0.61, 0.98)
0.76 (0.58, 0.95)
0.019

Perceived susceptibility

    Lower
172
165
251
1
1

    Higher
147
149
105
0.59 (0.46, 074)
0.61 (0.48, 0.78)
0.0001

Perceived severity

    Lower
138
105
96
1
1

    Higher
181
209
260
1.73 (1.36, 2.21)
1.42 (1.09, 1.86)
0.010

Perceived benefit

    Low
76
78
72
1
1

    High
243
236
284
1.17 (0.89, 1.54)
1.09 (0.82, 1.46)
0.547

Cues to action

    Low
171
184
208
1
1

    High
148
130
148
0.86 (0.69, 1.09)
0.89 (0.69, 1.115)
0.373

4. Discussion

This study found that only about one-third of the respondents had a high level of treatment adherence. Being a farmer, having family support, higher perceived consequences, perceived cyclical nature of hypertension, perceived susceptibility, and perceived severity of the disease had a significant association with treatment adherence.

We collected the data for this study using an interviewer-administered questionnaire, which is a preferred method when conducting a fairly large survey among the community with substantial low literacy levels, to minimize cognitive burden and increase response rate [38]. To minimize social desirability bias to self-reported adherence, we used a standard questionnaire and carefully selected and trained data collectors to conduct the interviews in a nonjudgmental manner. Thus, the adherence level reported in this study is a fair reflection of the practice in the study areas.

In our study, higher adherence to hypertensive medication as measured by MMAS-8 was only 36.0%, which is comparable to several reports from low- and middle-income countries [39–43]. However, it is lower than some other studies in Ethiopia such as that reported from Gondar hospital, 64.6% [28], Jimma Hospital, 55.7% [30], in selected hospitals of Addis Ababa, 66.8% [32], and Tikur Anbessa hospital in Addis Ababa, 69.2% [31]. The possible reasons for this difference could be variations in the population groups and cutoff points to adherence between the studies. Another explanation might be due to differences in the study population characteristics, differences in sample size, and the area covered by the research. The present study covered larger areas compared to the above studies. This low level of adherence can be averted by providing patients with meaningful information or health education about treatment adherence.

The findings of this research revealed that farmers were less likely to adhere to antihypertensive treatment compared to employed people. The Farmer is likely to be less educated and may have less information on the treatment adherence compared to the employed person [44, 45]. Therefore, healthcare providers should prepare health education to their clients based on their level of awareness by a due emphasis on farmers.

In this study, respondents who had family support were more likely to adhere to their treatment compared to those who have no family support. This finding is similar to the studies conducted in Northern Ethiopia, Mekele [29], and Nigeria [46], and an absence of household support had a strong negative effect on adherence among hypertensive patients. Likewise, studies in Congo reported that patients who received no support from family members about taking their medications were more likely to be noncompliant than the others [47]. The reason for this could be family support is important in the long-term management of hypertension, which requires a life-long change in the lifestyle of the affected person. Strong perceived family support will improve their self-worth and motivation. It is plausible that a motivated hypertensive patient will adhere to therapeutic plans and, therefore, achieve better blood pressure control.

While there may be no clear symptoms of hypertension, understanding how patients perceive hypertension (their illness perceptions) is necessary because, without this, treatment may not be appropriately tailored to their needs and belief systems. Understanding individuals’ perceptions about their illnesses provide a key for developing effective strategies to cope with chronic illnesses. Perception of a lower ability to control a health threat can be a barrier to one’s behavioral actions, or cognitive and emotional changes in illness representations because of somatic experiences. Higher perception of illness control is associated with lower anxiety, lower avoidance/denial of coping strategies, and positive reappraisal [48, 49]. In the present study, among illness perception dimensions perceived consequences and cyclical perception had a significant association with treatment adherence.

The respondent’s perception of the consequences of the disease was also positively related to treatment adherence, which was consistent with reports by other researchers [50, 51]. The perception of consequences has been shown to improve motivation to adhere to antihypertensive treatment [52].

Patients’ beliefs about how long their symptoms will last might impact their decisions to seek or not seek healthcare. Cyclical timeline refers to the belief of an individual that the expected symptoms will diminish after a certain period and then they might reappear at a certain time in the future. When the symptoms diminished, patients believe that it is cured and more likely to be nonadherent, including decreasing frequency and types of medication, taking medications intermittently, and deviating from the prescribed timing. In this regard, respondents who had higher cyclical perception were less likely to adhere to their treatment. The findings of this research were also supported by a study conducted by Chen et al. [49] indicated that a belief that the illness (hypertension) cyclical was associated with nonadherence to treatment.

In treating hypertension, understanding patient’s beliefs about medication adherence is fundamental because hypertension is often silent and asymptomatic. Thus, patients might undermine its severity and the significance of its management [27, 30, 53], leading to poor adherence to antihypertensive medication.

According to the Health Belief Model (HBM) people’s perception of risk predicts their behaviors, low-risk perception leads to undesired behaviors [52]. Hypertensive patients with low-risk perception may have a risky lifestyle and poor adherence to prescribed medications, which significantly compromise the control of the condition [54, 55].

Under the constructs of the HBM, those with a higher perceived susceptibility showed better adherence to antihypertensive medications [55, 56]. A study conducted among patients in South India found that medication adherence was significantly associated with all the six components of the HBM [57], and a Chinese study found that higher levels of perceived susceptibility, cues to action, and self-efficacy and a lower level of perceived barriers were significantly associated with better antihypertensive medication adherence [58]. However, in our study, only perceived susceptibility and perceived severity to hypertension showed a significant association with treatment adherence.

The importance of understanding treatment adherence to antihypertension medications in controlling the patient’s blood pressure and reducing hypertension-related complications to clinical practice cannot be overemphasized. Healthcare providers have to be aware of and understand patient’s beliefs about their illness and medications while caring for them and incorporating this belief in designing effective interventions to improve medication adherence through reducing barriers to taking medications.

Overall, 67.7% of patients were reporting a medium or high level of adherence to antihypertensive medication in this research. Among the study participants, farmers by occupation, having family support, perceived consequences, perceived cyclical nature of hypertension, perceived susceptibility, and perceived severity of the disease showed a significant association with treatment adherence. Illness perceptions and other beliefs may influence the actions of the individual and negatively or positively affect his or her health and taking medication. Therefore, it is important before and during treatment to assess patients’ views about their illness, symptoms, and treatments.

Data Availability

The datasets generated and/or analyzed during the current study are not publicly available due to some privacy reasons, but part of the raw dataset will be available from the corresponding author upon reasonable request.

Ethical Approval

An ethical approval letter was obtained from the institutional review board of Arsi University. Each study participant was adequately informed about the purpose, method, anticipated benefit, and risk of the study by the data collectors. The respondents’ right to refuse or withdraw from participating in the interview was fully maintained, and the information provided by each respondent is kept strictly confidential.

Consent

The respondents were informed about the purpose of the study, and their oral consent was obtained before the data collection. Anonymity was also maintained to ensure ensure confidentiality.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

Acknowledgments

The authors would like to thank Arsi University for the support they made to realize this research, hospitals, data collectors, and all participants for their enthusiastic participation.

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