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Perceived Illness and Treatment Adherence to Hypertension Among Patients Attending a Tertiary Hospital in Kathmandu, Nepal

Authors Shakya R , Shrestha S , Gautam R, Rai L, Maharjan S, Satyal GK, KC B , Rai MK

Received 10 July 2020

Accepted for publication 16 October 2020

Published 20 November 2020 Volume 2020:14 Pages 2287—2300

DOI https://doi.org/10.2147/PPA.S270786

Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 2

Editor who approved publication: Dr Johnny Chen



Rajina Shakya,1 Sunil Shrestha,2,3 Roshani Gautam,4 Lalita Rai,4 Sabindra Maharjan,5 Gita Kumari Satyal,6 Bhuvan KC,7 Mana Kumari Rai4

1Department of Nursing, Nobel College, Pokhara University, Sinamangal, Kathmandu, Nepal; 2Department of Pharmacy, Nepal Cancer Hospital and Research Center, Lalitpur, Nepal; 3Department of Pharmaceutical and Health Service Research, Nepal Health Research and Innovation Foundation, Lalitpur, Nepal; 4Maharajgunj Nursing Campus, Tribhuvan University, Institute of Medicine Maharajgunj, Kathmandu, Nepal; 5Central Bureau of Statistics, Kathmandu, Nepal; 6Female Surgical Ward, Department of Nursing, Tribhuvan University Teaching Hospital, Kathmandu, Nepal; 7School of Pharmacy, Monash University Malaysia, Subang Jaya 47500, Selangor, Malaysia

Correspondence: Rajina Shakya Email [email protected]
Bhuvan KC Email [email protected]

Introduction: Hypertension (HTN) is a silent killer, accountable for life-threatening complications. An individual’s illness perception may affect adherence to treatment which is crucial to prevent complications of HTN. The objective of this study was to identify illness perception and treatment adherence among patients with HTN in a tertiary hospital in Kathmandu, Nepal.
Methods: Descriptive correlational study was conducted in the out-patient department of Manmohan Cardiothoracic Vascular and Transplant Center, Kathmandu Nepal. Non-probability purposive sampling was used. A face-to-face interview was conducted from September to December 2018, using a structured questionnaire that included socio-demographic variables, illness perception questionnaire (revised) and Hill bone compliance to high blood pressure therapy scale. Data analysis was done by using descriptive and inferential statistics (chi-square test, Spearman rank correlation).
Results: Among 204 participants, 51% were male, 77% were literate, mean ± S.D. age was 60± 12. About 72% experienced headache and 88% said that headache is related to HTN. Behavioural factors and psychological factors were regarded as the leading cause of HTN. Almost 63% participants believed HTN as highly threatening illness. Higher scores in timeline (acute/chronic), personal control, and treatment control revealed that patients believed HTN as a chronic disease with a higher rate of personal and treatment control. Regarding treatment adherence, the mean score was 16.58 (SD = 2.08), and only 14.7% had perfect adherence. Participants were more adherent to medication and appointment keeping rather than reduce salt intake. Duration of HTN diagnosis (p=0.027) and duration under HTN medication (p= 0.021) were found to be significantly associated with treatment adherence. There was a significant positive correlation between illness perception and treatment adherence (ρ = 0.282, p< 0.01).
Conclusion: Illness perception and treatment adherence are correlated. Hence, it is beneficial to improve illness perception to achieve perfect treatment adherence. Reinforcement is essential to maintain adherence to both medications and behaviour therapy.

Keywords: hypertension, illness perception, Nepal, treatment adherence

Introduction

Hypertension (HTN) is a global public health problem and is an essential metabolic risk factor for cardiovascular disease. HTN has a critical role in expediting severe complications such as stroke, kidney failure, disability and premature deaths.1 HTN declines the quality of life of patients and also increases the financial and health burden among individuals and countries.2 Having no warning signs or symptoms (thus referred to as the silent killer) is the main reason that the majority of the hypertensive patients go undiagnosed.3 Globally, almost 31% of the adult population is affected by HTN, among which only 36.9% were under antihypertensive therapy, and 13.8% were having their HTN under control.4 The prevalence of HTN is highest in African countries (46%) followed by the Eastern Mediterranean (41%) and Southeast Asian countries (38%) and lowest in America (35%).5 Research reports show that two-third of the global population with HTN belong to low- and middle-income countries (LMICs)5 which indicate an alarming escalation in the prevalence, treatment and control of HTN in those countries than in developed countries.4

A systematic review by Huang et al, published in 2019 recognised HTN as a shocking condition in the Nepalese male, middle-aged (more than 40 years of age) population given the alarming state of prehypertension status which disturbs nearly 40% of the rural population.6 Prevalence of HTN in Nepal ranges from 23%-48%. A study conducted in Kathmandu, Nepal revealed that the prevalence of HTN has increased to three times within 25 years due to high salt intake and obesity.7 Studies conducted in different areas of Nepal show a variation in the prevalence of HTN. It is 41.55% in a rural area,8 28.9% in semi-urban,9 32.5% in an urban area10 and 48% in the mid-western region.11 Likewise, it is 25.1% in people above 18 years of age12 and in general, there is an increasing trend of HTN.

According to the Self–Regulatory Model of Illness (SRMI) developed by Leventhal et al in the 1980s, individuals seek to understand their illness by developing an understanding of its meaning, causes, consequences, how long it will last, and whether it can be cured or controlled. This illness perception may not be scientifically or medically validated but is formulated from personal experience (physical symptoms and emotions), social influences, and/or interaction with health-care providers.13

Beliefs about these components of illness help individuals to determine coping strategies.14 Patient’s perception of their illness is a decisive factor that determines their health-seeking behaviour.15

Adherence is regarded as a specific problem-focused coping strategy; patients weigh up whether the proposed treatment is consistent with what they believe about their illness in order to decide whether or not to adhere to it. Patients will evaluate the success of their treatment and may not continue with it if they perceive it to be unsuccessful.16 Thus, individual’s Illness perceptions and beliefs about medicine play a role in their preference for medicines for the treatment.17 Study shows that negative illness perceptions are associated with the more delayed recovery and increased healthcare use and this illness perceptions can be changed by offering appropriate knowledge.14

Evidence showed that patients’ views on illness affect adherence to self-management.18,19 Thus, understanding patient’s perceptions are essential for improving treatment adherence. A study has found that patients’ illness perceptions (identity or symptoms, cause, and control) have significant influences on adherence to prescribed medication and self-management.20 Several studies21–23 have shown that illness perception and beliefs about medication have a significant effect on adherence to treatment therapy in chronic diseases like HTN.

Medication adherence is essential for optimal blood pressure control, which significantly reduces the risk of cardiovascular disease.24 However, a study by Taheri-Kharameh et al conducted in Iran revealed a high proportion of patients with HTN who have poor medication adherence.22 Thus, non-adherence to antihypertensive therapy has become a therapeutic challenge.25,26 A cross-sectional study conducted in China showed that the prevalence of HTN was around 33%, and one-third of Chinese adults need antihypertensive treatment.27 However, only 46.4% of them were under treatment, and the overall control rate was 4.2%.27 Another study conducted among 154 patients with HTN in eastern Nepal revealed that only 56.5% of patients were adherent to antihypertensive therapy.28 The importance of understanding illness perception while providing medical advice and initiating treatment plans had been revealed in different studies.17 A cross-sectional study in Nepal among hypertensive patients has reported that the majority of patients have a moderate threatening view about illness and favoured taking medications rather than lifestyle modification.29

Various studies20,21,30 done in different countries suggest that a patient’s perception of illness can affect treatment adherence. Thus, we assume that patient’s perception of illness has an essential role in adherence to antihypertensive therapy. A limited number of studies28 have been done in the context of Nepal. With this background, the main objective of this study is to find out a relationship between perceived illness and treatment adherence of HTN among patients attending a tertiary level hospital. Interventions for health promotion based on illness perception will be beneficial for public health improvement.

Methods

Study Design and Setting

We adopted a descriptive correlational study design to carry out this study in Manmohan Cardiothoracic Vascular and Transplant Center (MCVTC) throughout September–December, 2018. MCVTC is 80 bedded specialised cardiac hospital under Tribhuvan University, Institute of Medicine (IOM). It was established in 2009 A.D. and is located within premises of Tribhuvan University Teaching Hospital (TUTH) in Kathmandu, Nepal. The center is now recognised as the tertiary referral center for cardiac cases from all over Nepal. It runs out-patient department (OPD) 6 days in a week and on an average of 50 patients per day visit the OPD for different cardiac cases along with HTN.

Study Population, Inclusion and Exclusion Criteria

The study population for the study were adult patients meeting the inclusion criteria; age 20 years and above, diagnosed with HTN and under anti-hypertensive therapy for at least six months. Both male and female patients attending the OPD in MCVTC were included in this study. The patient’s diagnosis and treatment status were confirmed by assessing OPD card, history taking along with medication history.

Those who can communicate in Nepali and willing to participate were included and patients who were hospitalised, medically unstable (having high B.P., symptoms like headache, dizziness at the time of interview) and unable to communicate were excluded from the study.

Sampling Procedure and Sample Size

We used a nonprobability purposive sampling technique in this study.

The sample size was calculated using Cochran formula no = Z2pq/e2, where no = minimum sample size, z = standard normal variate, p = estimated prevalence or proportion of population, q = 1-p, e = desired level of precision or margin of error and confidence interval = 95%. Therefore, z-score = 1.96. Estimated prevalence p = 56.5% (based on study conducted in eastern Nepal,28 q = 43.5%). Taking 95% confidence interval and 7% margin of error and 5% of non-response rate, the sample size was calculated 204.

Research Instrumentation

We used a structured interview schedule for data collection. English version instrument (Appendix I) was translated into the Nepalese language and examined by a bilingual translator. The translated version of the questionnaire was used for the interview, which included questions in three parts.

Socio-Demographic Information

Included questions related to socio-demographic data (age, sex, education, occupation, marital status, family type, income), disease and service-related variables (blood pressure, family history of HTN, duration of diagnosis, duration of medication, number of medications, monthly expenses for medication) which were prepared by the researcher based on literature review, consultation with an advisor, co-advisor, subject experts and peers.

Illness Perception Questionnaire-Revised (IPQ-R) in HTN

The illness perception scale was developed by Weinman & Petrie 199731 and was revised by Moss-Morris et al 200232 to assess the patient’s illness perception. The revised illness perception scale (IPQ-R) is based on Leventhal’s common-sense model (self-regulatory model)33 and is used for a variety of illnesses (HTN, diabetes mellitus, asthma, etc.). IPQ-R version has 3 sections to assess illness perception. In the first section identity of HTN is assessed using 14 commonly experienced symptoms. The responses were recorded as yes/no.

In the second section, seven dimensions of illness representations for HTN were assessed with 35 items, 5 items for timeline (acute/chronic), 4 items for timeline cyclical, 5 items for consequences, 6 items for personal control, 4 items for treatment control, 5 items for treatment coherence and 6 items for emotional representations. These 35 items were presented with five-point response scale: strongly disagree = 1, disagree = 2, neither agree nor disagree = 3, agree = 4 and strongly agree = 5. In the third section, 18 possible causes of hypertension are listed. Responses were recorded on a five-point response scale.

Scoring of Illness perception: based on scores of the second section. Low threatening illness perception = scores between 35 and 81.66. Moderate threatening illness perception = scores between 81.66 and 128.26. High threatening illness perception = 128.26–175 (Grouped frequency distribution, n.d.).

Part III: Hill Bone Compliance to High Blood Pressure Therapy Scale (HBCTS)

This scale assesses the patient’s behaviours for three important behavioural domains of high blood pressure treatment: reduced salt intake; appointment keeping and medication taking.34 It consists of 14 questions of 4 points Likert scale, which are: 9 questions related to medication adherence, 3 questions related to reduced salt intake and 2 questions related to appointment keeping. Scoring of Hill Bone scale. If the score is 14 = perfect adherence. If the score is >14 = non-perfect adherence (score 15–22 = optimal adherence, score >22 = poor adherence).35

Validity of Instrument

Both IPQ-R and HBCTS are standard tools. Their validity has been tested in different studies.32,34,36 Consultation with subject experts, advisor and co-advisor was done to maintain content validity of the translated instrument.

Reliability of Instrument

We did a pretesting of the instrument among 21 patients of TUTH who met the inclusion criteria, sample size to check for its clarity, sequentially, feasibility in administration and to calculate reliability. The modification of the questionnaire was done as required. Internal consistency was tested by calculating Cronbach’s alpha.37 The value of Cronbach’s alpha ranged from 0.700 to 0.855 for IPQ-R and 0.560 to 0.723 for HBCTS, which is considered as an acceptable value.

Ethical Considerations

The study was reviewed and approved by Institutional Review Committee (IRC), Institute of Medicine and research committee, Maharajgunj Nursing Campus, Tribhuvan university. This study complied with the Declaration of Helsinki. Before data collection, the respondents were informed about the purpose and objective of the study and written consent was obtained from each of them. The identity of the respondents was kept confidential.

Data Collection Procedure

Data collection was started after getting approval from the research committee, Maharajgunj Nursing Campus. In OPD of MCVTC, patients were screened by reviewing OPD cards for inclusion in the study; then the researcher introduced herself and explained the purpose of data collection. Voluntary participation was encouraged, and they were provided full authority to withdraw from the study at any time. Informed consent was obtained from each respondent, and confidentiality was maintained by assuring patients that the collected data will be used for study purposes only. Precautions were taken to protect rights and maintain the privacy of patients. Before the interview, clear instructions were given to maintain the quality of data. The researcher conducted face to face interviews at times and places convenient for the patient. The average time to complete the interview was approximately 30–35 minutes. After data collection, patients were provided education about HTN and its management as necessary, then leaflets on HTN were distributed, which was prepared by a team of researchers.

Data Analysis

The obtained data were processed and analysed by using statistical package for social sciences (SPSS) version 20. Data were analysed and interpreted based on the objectives of the study. Descriptive statistics (frequency, percentage, mean, standard deviation) were used to describe socio-demographic data, disease and service-related data and level of illness perception. Inferential statistics (chi-square test) was used to assess the association between demographic variables and treatment adherence. Spearman correlation was used to determine the relationship between illness perception and treatment adherence. The significance level was set at a p-value <0.05.

Results

Socio-Demographic Characteristics

The socio-demographic characteristics of the participants are summarised in Table 1. Of the 204 participants, 51% were male, and 49.1% were aged between 45 and 64 years. Mean age was 60±12 years. Among them, 58.3% reside within Kathmandu valley, and 56.4% belong to Brahmin and Chhetri ethnic group. Majority of participants (88.2%) were married, literate (77%) and almost half (50.5%) lived in a joint family.

Table 1 Socio-Demographic Characteristics of Participants (n= 204)

Disease and Service-Related Variables of Participants

Table 2 shows the disease and service-related variables of participants. The mean systolic and diastolic blood pressure was 127 mm of Hg and 82 mm of Hg, which was recorded on the patient’s OPD card. The mean duration of diagnosis and medication was 8 and 7 years, respectively. Participants took 73 minutes to reach a health facility and spent Nepalese Rupees (NPR) 942 [equivalent to USD 7.94] antihypertensive medications on an average.

Table 2 Disease and Service-Related Variables of Participants (n = 204)

Disease-Related Variables of Participants

Table 3 shows the disease-related variables of participants. More than one-fourth (28.5%) had a family history of hypertension. About half (55.9%) had comorbid conditions, and diabetes (48.3%) was most common. Majority of 80.9% were prescribed one pill per day, and amlodipine (58.8%) was common.

Table 3 Disease-Related Variables of Participants (n = 204)

Cognitive Perception of Illness of Participants: Symptoms Related to HTN

Table 4 summarises majority (78.4%) participants had experienced headaches since their illness and most of the participants (88.7%) had related headaches to be attributed to HTN. On average, 7 symptoms were experienced by participants, and nearly nine symptoms were related to hypertension.

Table 4 Cognitive Perception of Illness of Participants: Symptoms Related to HTN (n=204)

Mean Scores of IPQ-R and HBCTS

Table 5 shows mean scores and standard deviations of subscales of illness perception and treatment adherence. The high scores were obtained in the timeline (acute/chronic), personal control and treatment control subscales which indicate that participants mostly perceived HTN as a chronic disease, lasting for life long period. Mean score in timeline cyclical indicates the participants’ belief about a somehow stable nature of the illness. They believed that their illness could be controlled by personal behaviour and medical treatment. The mean scores in emotional representations, consequences and coherence represent that they agree their illness may affect them emotionally and may cause some physical consequences. They believed that they have some knowledge about their illness. The high mean scores in behavioral factors (diet, smoking, alcoholic, sedentary lifestyle) represent that these are perceived as significant causal factors for HTN, followed by psychological factors. Mean score of treatment adherence is 16.58. The proportion of perfect adherence in medication, salt restriction and appointment keeping were 49.5%, 37.7% and 56.9%, respectively.

Table 5 Mean Scores of IIPQ-R and HBCTS (n= 204)

Level of Perceived Illness and Treatment Adherence of Participants

Table 6 shows the illness perception level and treatment adherence level of participants. More than half (63.4%) had high threatening illness perception and only 14.7% were perfectly adherent to treatment therapy, and 83.8% were optimal adherent.

Table 6 Level of Perceived Illness and Treatment Adherence of Participants (n=204)

Association of Treatment Adherence and Selected Socio-Demographic Variables

Table 7 reveals that there is no statistically significant association between treatment adherence and demographic variables (age, sex, education status, marital status and family type, occupation, and monthly income).

Table 7 Association of Treatment Adherence and Selected Socio-Demographic Variables (n= 204)

Association of Treatment Adherence and Selected Disease-Related Variables

Table 8 shows that there was a significant statistical association between duration of diagnosis and treatment adherence and duration of medication and treatment adherence of participants (p-value 0.027 and 0.021, respectively). In contrast, there was not statistical association between treatment adherence and family history of HTN, comorbidity, duration to reach a health facility.

Table 8 Association of Treatment Adherence and Selected Disease-Related Variables (n= 204)

Correlations Between Perceived Illness and Treatment Adherence Variables

Table 9 shows that significant associations were found between different IPQ-R scores and overall treatment adherence except for identity, emotional and psychological attributions. Regarding treatment adherence, medication has a significant association with IPQ-R scores, whereas salt restriction and appointment keeping have no significant association with IPQ-R scores. Coherence is negatively correlated with overall treatment adherence and medication. All other domains of IPQ-R are positively co-related with treatment adherence. The strongest correlation was found between scores of treatment control and medication (ρ = 0.364, p <0.001).

Table 9 Correlations Between Perceived Illness and Treatment Adherence Variables (n=204)

Discussion

We examined illness perception, level of treatment adherence and their relationship among patients with HTN in Kathmandu, Nepal. Our study revealed that people regarded HTN as a highly threatening illness. The majority of the population have an acceptable level of treatment adherence, yet, interventions are required to achieve perfect adherence. The high percentage of adherence level may be due to the high literacy rate and urban locality; however, we did not find a significant association between the two. Our study showed that the duration of diagnosis and duration of treatment therapy was associated with perfect adherence. It shows that there is a significant correlation between illness perception and treatment adherence.

Illness Perception of Hypertension

Our study result shows that most of the patients (63.2%) had a highly threatening view of HTN. This finding is nearly similar to the studies on illness perception, that showed moderate threatening view.15,29,38 Counselling and education programs are frequently organised in the hospital where participants were made aware of nature, treatment, and control of HTN. However, participants believed they had minimal understanding of HTN. As opposed to the findings of our study, Nagarkar et al revealed a lower total illness perception score (34 out of 80) that indicated lower threatening view of disease by patients.39 Also, illness perception of HTN was different for urban and rural patients. Urban patients with HTN displayed more threatening perception of their illness, experienced more symptoms, were more concerned and believed the treatment was helpful to control illness than rural patients.39

Majority of participants believed HTN to be chronic, the permanent illness which could bring serious consequences, emotional disturbances. This finding is in line with studies by Rahman et al.40 Maharjan et al,29 Kolb et al,41 which reported perceived chronic nature and devastating consequences of HTN. On the contrary study by Lo et al found low scores in consequences, emotional, timeline cyclical and coherence which means participants perceived that HTN has minimal negative and emotional consequences, is stable and they had no clear understanding of HTN.42 Similarly, the study by Nivedita also found poor understanding of illness and more emotional problems related to HTN among patients.43

Hypertension is considered an asymptomatic disease. Our study showed that the majority of participants experienced headache, fatigue, dizziness and blurred vision and related as the symptoms of HTN. Previous studies by Maharjan et al,29 Lo et al,42 Kolb et al41 and Nivedita,43 also reported similar findings as this study, which stated that patients experienced headache, palpitations and dizziness which were related to HTN. Most of the people in Nepal, visit the hospital, only if they have symptoms or health issues. This may be the reason for perceiving HTN as symptomatic as they were diagnosed after symptom experience.

Though patients perceived HTN as highly threatening, they believed that personal efforts and treatment modalities could control their high blood pressure and also prevent complications. Studies by Maharjan et al29 and Ross et al21 are in line with these findings that reported HTN as a chronic disease which can be controlled with regular medication and behaviour modification. Rahman et al40 also revealed that patients strongly believed HTN to be controlled by medications but were resistant for behaviour modification. On comparing scores, treatment control has a higher score than personal control, which means they have a strong belief that medication will help them control HTN.

In contrast to the findings of our study, a study in India found relatively low mean scores in treatment control, timeline, personal control and coherence which means participants perceived stable nature of the illness, ineffective control through treatment and personal effort and inadequate understanding of the illness.43 Different settings of the study too might have contributed to these findings.

Regarding causal attributions to HTN, the majority of participants strongly believed that diet is the primary causal factor for HTN, followed by stress and worry, and family problems. This finding aligns with a study conducted by Maharjan et al where the majority of participants (80.11%) believed the cause of HTN to be diet and stress.29 A similar study in line with the findings was conducted by Lo et al which revealed that participants believed life stressors, e.g. emotional state, mental attitude, and family problems were the primary cause of HTN.42 The mixed-method study conducted in different countries of Asia (Malaysia, Hong Kong, South Korea, Taiwan, Indonesia, Thailand, and Philippines) showed consistent findings to the present study. The study revealed that patients perceived HTN as a chronic lifelong condition that can lead to severe consequences such as stroke, paralysis and heart attack and also reported stress, excess salt intake, alcohol consumption, smoking as the significant contributors to HTN.40 Salty foods and alcohol are excessively consumed by the Nepalese people. They believed these eating habits as the principal cause of HTN. It is important to note that most of the causes are modifiable (diet, stress, family problems); therefore, it is essential to promote a lifestyle modification for better blood pressure control by raising awareness about HTN and healthy behavior through formal and informal education.

Treatment Adherence

Adherence to treatment therapy is essential to prevent complications of hypertension. Our study found that most of the population (83.8%) had an optimal or acceptable level of adherence to treatment, but only 14.7% had perfect adherence to all dimension of treatment: medication (49.5%), salt restriction (37.7%) and appointment keeping (56.9%). Majority of participants in this study were literate and resided within an urban area. Also, the data was collected in a tertiary level hospital where patients were provided with appropriate teaching and counselling. This might have contributed to the high prevalence of optimal adherence among participants. Since the dimensions of treatment adherence we used were different, the study result might not be comparable with previous studies.

Our study findings are also supported by other studies from Nepal, where the overall adherence score was at a moderate level, and the majority had high treatment adherence level.44 Studies carried out in other countries have reported a higher adherence level viz. Beruit 71%,38 Europe 69.8%,45 Sudan 70.5%,46 Ethiopia 75.1%,47 Mangalore 78.7%,48 Pakistan 77%,49 Lebanon 85%.50

In our study, perfect adherence to medication was 49.5% which was nearly similar to the findings of studies in Kerala 46%,51 Nepal 44.1% by Bhandari et al,28 China 44.1–56.5% Lo et al,42 Palestine 45.7%.52 In contrast to our study findings, Aslolami et al found only 27% perfectly adhered to medication53 which might be due to those people who find it easy to adhere to medication rather than behaviour change like salt restriction. This shows that adherence to medication is low in developing countries and higher in developed countries. This may be due to their knowledge level, availability and cost of medications. However, the finding of our study also indicated adherence to treatment therapy, including medication and behaviour change, was very low. This indicates that we need to promote adherence to medication, behaviour therapy like salt restriction and appointment keeping. Similarly, another reason may be due to the number of pills that patients were taking. Our study found that nearly 80% of patients were taking the only pill, so they were more adherent. A study in Zambia reported that patients taking 3 or more pills were likely to be non-adherent, where adherence prevalence was 70%.54 Patients with multiple pills might forget or confuse about medicines which lead to non-adherence. The study showed there is a significant association between treatment adherence and duration of diagnosis (p = 0.043) and the duration of antihypertensive medicine intake (p = 0.023). Association between treatment adherence and socio-demographic, disease and drug-related variables was not statistically significant. A study in Nigeria also showed no significant differences in adherence to treatment between males and females.55 The study is in line with the study conducted in China which concluded that the duration of medication and history of diagnosis could be related to better adherence.56

In contrast, to present study findings, many studies have shown a significant association of treatment adherence and demographic variables as poor adherence is associated with age >50,47,48 males,45,48 uneducated,48,53,57 unemployed, retired,48,57 having comorbidities.53 Good adherence is associated with urban residents,47,57 married,58,59 annual household income, medical insurance,58 taking fewer pills daily and having knowledge of HTN and its treatment.47 In contrast, to present study findings, positive association (p =0.01) between male and low adherence was found, and no significant association was seen between treatment adherence and other demographic variables (marital status, residence and professional background) in that study.45 Similarly, a study in Ethiopia showed that urban residence, taking less than two pills per day and having knowledge about HTN and treatment, were positively and significantly associated with treatment adherence. However, age more than 60 years was negatively and significantly associated with treatment adherence. In contrast to findings of the current study, a cohort study found that only 55.9% patient was adherent to treatment and older age and marital status were associated with better adherence.58

A study in Mangalore revealed that poor compliance among less educated and unemployed or retired male participants over 50 years.48 Another study findings showed that the level of education and comorbidities were significantly associated with the level of adherence.53 Similarly, the findings of a study by Zhang et al contradict the present study findings, which revealed that age, residence, educational level, annual household income, and out-patient medical reimbursement were statistically associated with non-adherence (p< 0.05).57 This means patients living in rural, low annual income and with no medical insurance reimbursement had a significantly higher rate of non-adherence.

Illness Perception and Treatment Adherence

Our study findings suggested a significantly positive relationship between illness perception and treatment adherence which is in line with predictions of common sense model.33 The findings are supported by a study conducted by Rajpura & Nayak (2014) which reported a significant correlation (r=0.332, p =0.01) between illness perception scores and medication adherence scores suggesting high, threatening perceptions of illness would translate into higher levels of medication adherence.17 The results were also consistent with the findings of previous studies by Chen et al 2009,60 Ross et al 2004,21 Hsiao et al 2012.30 On the contrary, the study done by Saarti et al showed that the patient’s adherence to treatment is related to blood pressure control. It is associated with treatment satisfaction rather than illness perception.38 The difference in results may be due to the use of different tools to assess illness perception and treatment adherence.

Furthermore, the correlation between dimensions of illness perception and medication adherence were also established in this study. However, association with other dimensions of treatment adherence was not statistically significant. Timeline (acute/chronic), timeline cyclical and consequences were positively correlated with overall treatment adherence and medication subscales. This signifies that people are likely to adhere to treatment if they believed their illness stays with them forever and have severe complications. In oppose to this, Hasio et al 2012 found that patients who believed HTN as acute illness were more adherent.30

Our study revealed positive associations between medication adherence and cure/control subscales. A strong correlation was seen among treatment control and medication adherence. People who have a strong belief that medicine will cure their illness and prevent complications were more adherent to medications. Also, the perception of personal control is associated with medication adherence. Similarly, a study conducted in Iran aligns with findings of our study, which concluded that patients scored higher than mean scores in treatment adherence and personal control and understanding were significantly correlated with adherence.22 However, Ross et al 2004 reported a negative association between personal control and treatment adherence.21

We found that emotional representation and identity showed no significant association and coherence was negatively associated with treatment adherence. In previous studies, it was mentioned that patients age and health might impact emotional representation.29 In our study, the mean age was 60 and blood pressure was 127/82mm of Hg, and most of the patients had no severe complications and emotional consequences of HTN. On the contrary, studies by Hasio et al.30 Ross et al21 and Zuglej et al23 reported strong emotional perception to affect treatment adherence. A study in Taiwan is in line with the findings of the present study, which showed that there are significant associations between illness perception scores and medication adherence scores except for identity, timeline, coherence, and emotional representations.

Regarding causal factors, the findings indicated that those who perceived low immunity as the cause of hypertension are more likely to adhere to treatment therapy. This is supported by the study which reported no association between adherence and knowledge of HTN or its underlying cause.53 So improving understanding of HTN and its causes may promote adherence.

We recommend an awareness program regarding personal and treatment control, and the nature of disease should be launched for patients to increase their understanding of hypertension. Treatment adherence behaviour of young and newly diagnosed patients should be monitored closely. Similar studies can be conducted in a community setting on a large scale to make the findings generalisable, and a comparative study in urban and rural settings can be conducted to compare the treatment adherence level.

Limitations

Our study has some limitations which need to be acknowledged. First, the study design was a cross-sectional study that measured illness perception and treatment adherence among patients at a point of time. Therefore, any changes in the trend of these variables over time could not be assessed. Second, the study was conducted using a non-probability sampling technique. Thus, the findings of the study may not be generalised beyond this population. Third, the study population were recruited from a hospital setting so that the findings might have been biased towards adherence which may be the reason behind data not fitting the logistic regression model. Fourth, the tool used for assessing treatment adherence is self-reporting tool; thus, there is a risk of reporting bias and social desirability bias.

Conclusion

In conclusion, HTN was perceived as highly threatening illness. Patients believed HTN was a chronic disease of unstable nature which can have some severe complications and emotional impacts. To the bright side, patients perceived that HTN could be controlled by medication and personal efforts.

Regarding treatment adherence, one in five have perfect adherence, and remaining have optimal adherence to treatment. Patients were more adherent to medication rather than salt restriction. Treatment adherence was not associated with demographic variables but significantly associated with duration of diagnosis and duration of medication. There was a significant positive correlation between treatment adherence and illness perception of HTN. Perception of the timeline, treatment control, personal control, consequences have a significant role in improving treatment adherence. Hence, the findings suggest that motivation is needed for newly diagnosed patients for adherence, and health personnel can facilitate patients to change their illness perception to enhance treatment adherence.

Data Sharing Statement

The datasets of this study are available from the corresponding author on reasonable request.

Ethical Considerations

The study was reviewed and approved by Institutional Review Committee (IRC), Institute of Medicine and research committee, Maharajgunj Nursing Campus, Tribhuvan University. This study complied with the Declaration of Helsinki. Before data collection, the respondents were informed about the purpose and objective of the study and written consent was obtained from each of them. The identity of the respondents was kept confidential.

Acknowledgments

The authors are thankful for the support provided by the University Grant Commission, Tribhuvan University, Institute of Medicine, Institutional Review Committee, Maharajgunj nursing campus, Dr Surya Devkota, Mrs Bimala Neupane (Manmohan Cardiothoracic Vascular and Transplant Center). We are grateful to Assistant Professor Yvonne Commodore-Menash, Mr Bibhav Adhikari, Mr Tirtha Paudel and all the participants and assistants who made this study possible.

Funding

Partial financial support of Nepalese Rupees NPR 25,000 (Equivalent to USD 209) was given by the University Grant Commission (UGC), Sano Thimi, Bhaktapur, Nepal under faculty research grant for conducting this study.

Disclosure

Rajina Shakya reports faculty research grants from University Grant Commission, Nepal, outside the submitted work. The authors declare no other potential conflicts of interest for this work.

References

1. Drozdz D, Kawecka-Jaszcz K. Cardiovascular changes during chronic hypertensive states. Pediatr Nephrol. 2014;29(9):1507–1516. doi:10.1007/s00467-013-2614-5

2. Gaziano TA, Bitton A, Anand S, Weinstein MC. The global cost of nonoptimal blood pressure. J Hypertens. 2009;27(7):1472–1477. doi:10.1097/HJH.0b013e32832a9ba3

3. Chobanian AV, Bakris GL, Black HR, et al. Seventh report of the joint national committee on prevention, detection, evaluation, and treatment of high blood pressure. Hypertension. 2003;42(6):1206–1252.

4. Mills KT, Bundy JD, Kelly TN, et al. Global disparities of hypertension prevalence and control: a systematic analysis of population-based studies from 90 countries. Circulation. 2016;134(6):441–450. doi:10.1161/CIRCULATIONAHA.115.018912

5. World Health Organisation. Raised blood pressure. 2018. Available from: https://www.who.int/gho/ncd/risk_factors/blood_pressure_prevalence_text/en/. Accessed October 31, 2019.

6. Huang Y, Guo P, Karmacharya BM, Seeruttun SR, Xu DR, Hao Y. Prevalence of hypertension and prehypertension in Nepal: a systematic review and meta-analysis. Glob Health Res Policy. 2019;4:11. doi:10.1186/s41256-019-0102-6

7. Vaidya A, Pathak RP, Pandey MR. Prevalence of hypertension in Nepalese community triples in 25 years: a repeat cross-sectional study in rural Kathmandu. Indian Heart J. 2012;64(2):128–131. doi:10.1016/S0019-4832(12)60045-5

8. Kafle R, Sharma D, Paudel N, Sapkota S, Alurkar V. Prevalence and associated risk factors of hypertension in a rural community of Western Nepal: a Cross Sectional Study. J Adv Intern Med. 2018;7(1):11–16. doi:10.3126/jaim.v7i1.19577

9. Koju R, Manandhar K, Gurung R, Pant P, Bedi T. Prevalence of hypertension in semi-urban area of Nepal. Nepalese Heart J. 2010;7(1):35–39. doi:10.3126/njh.v7i1.8500

10. Dhungana RR, Pandey AR, Bista B, Joshi S, Devkota S. Prevalence and associated factors of hypertension: a community-based cross-sectional study in municipalities of Kathmandu, Nepal. Int J Hypertens. 2016;2016:1–10. doi:10.1155/2016/1656938

11. Khanal MK, Dhungana RR, Bhandari P, Gurung Y, Paudel K, Kiechl S. Prevalence, associated factors, awareness, treatment, and control of hypertension: findings from a cross sectional study conducted as a part of a community based intervention trial in Surkhet, Mid-western region of Nepal. PLoS One. 2017;12(10):e0185806. doi:10.1371/journal.pone.0185806

12. Pyakurel P, Yadav DK, Thapa J, et al. Prevalence and associated risk factor of hypertension among individuals of age 18–59 years in South-eastern Nepal: a cross-sectional study. Nepalese Heart J. 2019;16(1):19–26. doi:10.3126/njh.v16i1.23894

13. Leventhal H, Meyer D, Nerenz D. The common sense representation of illness danger. In Rachman S, editor.Medical Psychology. Vol II. New York: Pergamon Press. 1980:7–30.

14. Petrie KJ, Weinman J. Why illness perceptions matter. Clin Med (Lond). 2006;6(6):536–539. doi:10.7861/clinmedicine.6-6-536

15. Norfazilah A, Samuel A, Law P, et al. Illness perception among hypertensive patients in primary care centre UKMMC. Malays Fam Physician. 2013;8(3):19–25.

16. Browning KK, Wewers ME, Ferketich AK, Otterson GA, Reynolds NR. The self-regulation model of illness applied to smoking behavior in lung cancer. Cancer Nurs. 2009;32(4):E15–E25. doi:10.1097/NCC.0b013e3181a0238f

17. Rajpura JR, Nayak R. Role of illness perceptions and medication beliefs on medication compliance of elderly hypertensive cohorts. J Pharm Pract. 2014;27(1):19–24. doi:10.1177/0897190013493806

18. Costa E, Giardini A, Savin M, et al. Interventional tools to improve medication adherence: review of literature. Patient Prefer Adherence. 2015;9:1303–1314.

19. Figueiras M, Marcelino DS, Claudino A, Cortes MA, Maroco J, Weinman J. Patients’ illness schemata of hypertension: the role of beliefs for the choice of treatment. Psychol Health. 2010;25(4):507–517. doi:10.1080/08870440802578961

20. Chen S-L, Tsai J-C, Chou K-R. Illness perceptions and adherence to therapeutic regimens among patients with hypertension: a structural modeling approach. Int J Nurs Stud. 2011;48(2):235–245. doi:10.1016/j.ijnurstu.2010.07.005

21. Ross S, Walker A, MacLeod MJ. Patient compliance in hypertension: role of illness perceptions and treatment beliefs. J Hum Hypertens. 2004;18(9):607–613. doi:10.1038/sj.jhh.1001721

22. Taheri-Kharameh Z, Hazavehei SMM, Ramezani T, Vahedi A, Khoshro M, Sharififard F. The assessment of illness perception and adherence to therapeutic regimens among patients with hypertension. J Edu Community Health. 2016;3(2):9–15. doi:10.21859/jech-03022

23. Žugelj U, Zupančič M, Komidar L, Kenda R, Varda NM, Gregorič A. Self-reported adherence behavior in adolescent hypertensive patients: the role of illness representations and personality. J Pediatr Psychol. 2010;35(9):1049–1060. doi:10.1093/jpepsy/jsq027

24. Kim S, Shin DW, Yun JM, et al. Medication adherence and the risk of cardiovascular mortality and hospitalization among patients with newly prescribed antihypertensive medications. Hypertension (Dallas, Tex: 1979). 2016;67(3):506–512. doi:10.1161/HYPERTENSIONAHA.115.06731

25. Krousel-Wood M, Thomas S, Muntner P, Morisky D. Medication adherence: a key factor in achieving blood pressure control and good clinical outcomes in hypertensive patients. Curr Opin Cardiol. 2004;19(4):357–362. doi:10.1097/01.hco.0000126978.03828.9e

26. Peacock E, Krousel-Wood M. Adherence to antihypertensive therapy. Med Clin North Am. 2017;101(1):229–245. doi:10.1016/j.mcna.2016.08.005

27. Lewington S, Lacey B, Clarke R, et al. The burden of hypertension and associated risk for cardiovascular mortality in China. JAMA Intern Med. 2016;176(4):524–532. doi:10.1001/jamainternmed.2016.0190

28. Bhandari B, Bhattarai M, Bhandari M, Ghimire A, Pokharel PK, Morisky DE. Adherence to antihypertensive medications: population based follow up in Eastern Nepal. J Nepal Health Res Counc. 2015;13(29):38–42.

29. Maharjan S, Chinnawong T, Kritpracha C. Illness perception among patients with hypertension in Nepal. GSTF J Nurs Health Care. 2017;4(2).

30. Hsiao C-Y, Chang C, Chen C-D. An investigation on illness perception and adherence among hypertensive patients. Kaohsiung J Med Sci. 2012;28(8):442–447. doi:10.1016/j.kjms.2012.02.015

31. Weinman J, Petrie KJ. Illness perceptions: a new paradigm for psychosomatics? J Psychosom Res. 1997;42(2):113–116. doi:10.1016/S0022-3999(96)00294-2

32. Moss-Morris R, Weinman J, Petrie K, Horne R, Cameron L, Buick D. The revised Illness Perception Questionnaire (IPQ-R). Psychol Health. 2002;17(1):1–16. doi:10.1080/08870440290001494

33. Leventhal H, Phillips LA, Burns E. The Common-Sense Model of self-regulation (CSM): a dynamic framework for understanding illness self-management. J Behav Med. 2016;39(6):935–946. doi:10.1007/s10865-016-9782-2

34. Kim MT, Hill MN, Bone LR, Levine DM. Development and testing of the hill-bone compliance to high blood pressure therapy scale. Prog Cardiovasc Nurs. 2000;15(3):90–96. doi:10.1111/j.1751-7117.2000.tb00211.x

35. Nashilongo MM, Singu B, Kalemeera F, et al. Assessing adherence to antihypertensive therapy in primary health care in Namibia: findings and implications. Cardiovasc Drugs Ther. 2017;31(5–6):565–578. doi:10.1007/s10557-017-6756-8

36. Arat S, Van den Zegel A, Van Rillaer M, et al. Development and preliminary evaluation of the validity and reliability of a revised illness perception questionnaire for healthcare professionals. BMC Nurs. 2016;15:34. doi:10.1186/s12912-016-0156-4

37. Tavakol M, Dennick R. Making sense of Cronbach’s alpha. Int J Med Educ. 2011;2:53–55. doi:10.5116/ijme.4dfb.8dfd

38. Saarti S, Hajj A, Karam L, et al. Association between adherence, treatment satisfaction and illness perception in hypertensive patients. J Hum Hypertens. 2016;30(5):341–345. doi:10.1038/jhh.2015.86

39. Nagarkar A, Gadhave S, Gund P, Sharma I, Choure A. Comparative study of illness perception among Hypertensive Patients in India. 2013.

40. Rahman ARA, Wang J-G, Kwong GMY, et al. Perception of hypertension management by patients and doctors in Asia: potential to improve blood pressure control. Asia Pac Fam Med. 2015;14(1):2. doi:10.1186/s12930-015-0018-3

41. Kolb SE, Zarate-Abbott PR, Gillespie M, Deliganis J, Norgan GH. Perceptions about high blood pressure among mexican american adults diagnosed with hypertension. Fam Community Health. 2011;34(1):17–27. doi:10.1097/FCH.0b013e3181fdec84

42. Lo SH, Chau JP, Woo J, Thompson DR, Choi KC. Adherence to antihypertensive medication in older adults with hypertension. J Cardiovasc Nurs. 2016;31(4):296–303. doi:10.1097/JCN.0000000000000251

43. Nivedita S. Illness perception and coping among hypertension patients. Res J Recent Sci. 2015;2277:2502.

44. Maharjan S. Illness Perception and Treatment Adherence Among Patients with Hypertension in Nepal. Prince of Songkla University; 2016.

45. Tilea I, Petra D, Voidazan S, Ardeleanu E, Varga A. Treatment adherence among adult hypertensive patients: a cross-sectional retrospective study in primary care in Romania. Patient Prefer Adherence. 2018;12:625–635. doi:10.2147/PPA.S162965

46. Omar SM, Elnour O, Adam GK, Osman OE, Adam I. Assessment of blood pressure control in adult hypertensive patients in eastern Sudan. BMC Cardiovasc Disord. 2018;18(1):26. doi:10.1186/s12872-018-0769-5

47. Teshome DF, Bekele KB, Habitu YA, Gelagay AA. Medication adherence and its associated factors among hypertensive patients attending the Debre Tabor General Hospital, northwest Ethiopia. Integr Blood Press Control. 2017;10:1–7. doi:10.2147/IBPC.S128914

48. Joseph N, Chiranjeevi M, Sen S, Singh P, Saini M, Beg S. Awareness on hypertension and its self-management practices among hypertensive patients attending outreach clinics of a medical college in South India. Kathmandu Univ Med J. 2016;14(55):202–209.

49. Hashmi SK, Afridi MB, Abbas K, et al. Factors associated with adherence to anti-hypertensive treatment in Pakistan. PLoS One. 2007;2(3):e280. doi:10.1371/journal.pone.0000280

50. Abbas H, Kurdi M, Watfa M, Karam R. Adherence to treatment and evaluation of disease and therapy knowledge in lebanese hypertensive patients. Patient Prefer Adherence. 2017;11:1949–1956. doi:10.2147/PPA.S142453

51. Balasubramanian A, Nair SS, Rakesh PS, Leelamoni K. Adherence to treatment among hypertensives of rural Kerala, India. J Fam Med Prim Care. 2018;7(1):64–69. doi:10.4103/jfmpc.jfmpc_423_16

52. Al-Ramahi R. Adherence to medications and associated factors: a cross-sectional study among palestinian hypertensive patients. J Epidemiol Glob Health. 2015;5(2):125–132. doi:10.1016/j.jegh.2014.05.005

53. Alsolami F, Correa-Velez I, Hou X-Y. Factors affecting antihypertensive medications adherence among hypertensive patients in Saudi Arabia. Am J Med Sci. 2015;5(4):181–189.

54. Mweene MD, Banda J, Andrews B, Mweene M, Lakhi S. Factors associated with poor medication adherence in hypertensive patients in Lusaka, Zambia. Med J Zambia. 2010;37(4):252–261.

55. Atulomah N, Florence O, Oluwatosin A. Treatment adherence and risk of non-compliance among hypertensives at a Teaching Hospital in Ogun state, southwest Nigeria. Acta SATECH. 2010;3(2):143–149.

56. Schmieder RE, Ott C, Schmid A, et al. Adherence to antihypertensive medication in treatment‐resistant hypertension undergoing renal denervation. J Am Heart Assoc. 2016;5(2):e002343. doi:10.1161/JAHA.115.002343

57. Zhang Y, Li X, Mao L, et al. Factors affecting medication adherence in community-managed patients with hypertension based on the principal component analysis: evidence from Xinjiang, China. Patient Prefer Adherence. 2018;12:803–812. doi:10.2147/PPA.S158662

58. Alhaddad IA, Hamoui O, Hammoudeh A, Mallat S. Treatment adherence and quality of life in patients on antihypertensive medications in a Middle Eastern population: adherence. Vasc Health Risk Manag. 2016;12:407–413. doi:10.2147/VHRM.S105921

59. Joho AA. Factors Affecting Treatment Compliance Among Hypertension Patients in Three DISTRICT Hospitals-Dar Es Salaam. Muhimbili University of Health and Allied Sciences; 2012.

60. Chen SL, Tsai JC, Lee WL. The impact of illness perception on adherence to therapeutic regimens of patients with hypertension in Taiwan. J Clin Nurs. 2009;18(15):2234–2244. doi:10.1111/j.1365-2702.2008.02706.x

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