Background
As disease burdens shift from infectious to non-communicable diseases, hypertension is a principal precursor to cardiovascular diseases and a main cause of death globally [
1,
2]. About 80% of these deaths were recorded in low- and middle- income countries and projections indicate that the highest non-communicable mortality rates would be recorded in these countries by 2020 [
3]. Hypertension affects approximately 25% of urban and 20% of rural Ghanaian populations [
4] and 11% - 42% of Africans [
2,
5‐
7]. A global hypertension prevalence of 26% is projected to ascend to 29% by the year 2025 [
8].
Like patients with other chronic medical conditions, hypertensive patients experience many profound emotions which increase their risk for the development of mental health disorders particularly anxiety and depression [
9,
10]. Imperative to the management of hypertension is the need for patients to adhere to pharmacological and non-pharmacological therapies and these negative emotions may adversely influence their adherence behaviour [
11].
Anxiety and lower adherence rates have been observed for asthma, heart failure, haemodialysis and contraceptive use [
12‐
15], although Kim et al. [
16] noticed greater adherence among the majority of their patients with anxiety disorder.
Depression is a burdensome disease of global importance [
17] and although prevalent, it is mostly undiagnosed in patients with hypertension [
18]. Some relationship has been observed between depression and non-adherence to medical therapy [
19,
20] and a high number of prescribed medications were listed as one of the contributing factors for the development of depressive symptoms in hypertension [
21]. However not all studies successfully showed a relationship between depressive symptoms and adherence [
14,
22].
The stress of having a chronic medical condition may potentially influence medication adherence behaviour; yet, earlier studies on emotional determinants of adherence have largely focused on depression and anxiety [
12,
14]. In clinical settings, stress has repeatedly been used as a euphemism for negative emotions, particularly to address undesirable psychiatric diagnostic labelling [
23]. Stress negatively influenced medication adherence behaviour in HIV/AIDS [
24] and acute coronary syndrome [
25]. Empirical evidence showed the importance of stress in the onset and worsening of essential hypertension [
26], yet there is a dearth of information associating stress and medication adherence in hypertension management.
Drawing a causal relationship between anxiety, depression and stress, in hypertension and medication adherence may be difficult [
19]; but on the other hand, overlooking the association may further decrease attempts to manage the burden of medication non-adherence. For Ghanaian patients with hypertension, this interaction between hypertension and symptoms of anxiety, depression and stress remains largely unexplored and incompletely understood in terms of its prevalence and effect on medication adherence. To fill this knowledge gap, the study sought to ascertain 1) whether hypertensive patients exhibited symptoms of anxiety, depression and stress; 2) whether individuals experiencing anxiety, depression and stress symptoms were more likely to be non-adherent than patients without these symptoms; and 3) whether patients’ belief systems had a relationship with anxiety, depression and stress symptoms.
Methods
Study design and setting
A hospital-based cross-sectional study design was used. The study was carried out at the two major teaching hospitals in Ghana; Korle-Bu Teaching Hospital (KBTH), Accra and Komfo Anokye Teaching Hospital (KATH), Kumasi. The description of the study site has previously been reported [
27].
Participants
Two hundred (200) hypertensive outpatients each were recruited from KBTH and KATH. Eligibility to participate in the study was based on the following: A diagnosis of hypertension only or hypertension with other co-morbid conditions, reporting prescription of at least one antihypertensive medication for a minimum of two months and an age of at least eighteen years. The sample did not include pregnant women (because of the possibility of gestational hypertension which may resolve after delivery), newly diagnosed patients as well as the physically and mentally incapacitated [
27].
Measures
After informed written consent, a standardized quantitative assessment tool was used to collect data concurrently from the hypertensive patients attending KBTH and KATH between May and October, 2012. The information gathered covered three areas: i) demographic characteristics; ii) anxiety, depression and stress measures using the Depression Anxiety Stress Scale (DASS) – 21 [
28]; iii) medication adherence behaviour using the Morisky Medication Adherence Scale [
29]; and iv) the Spiritual Perspective Scale [
30]. Participants were asked about their age, sex, place of residence, religious affiliation, marital status, educational level, and duration of hypertensive diagnosis.
The DASS is a 21 item self-report inventory that measures the negative emotional states of depression, anxiety and stress. Each of the three scales comprised seven items with related content. The depression subscale assessed dysphoria, hopelessness, devaluation of life, self-depreciation, and lack of interest/involvement, anhedonia, and inertia. The anxiety subscale measured autonomic arousal, skeletal muscle effects, situational anxiety, and subjective experience of anxious affect. The stress subscale measured relaxation difficulty, nervous arousal, agitation, irritability and impatience. Participants were requested to use a 4-point severity/frequency scale to rate the extent to which they had experienced each negative state over the past week. Reliability for the three scales is 0.71 for depression, 0.79 for anxiety and 0.81 for stress [
28]. The DASS anxiety subscale has a correlation coefficient of 0.81 with the Beck Anxiety Inventory whereas the DASS depression subscale had 0.74 with the Beck Depression Inventory [
31,
32].
The MMAS is an 8-item scale used to measure medication adherence behavior in hypertensive patients and responses are categorized as low adherence (<6), medium adherence (6 - < 8), and high adherence (8). Low and moderate scores were grouped as poor adherence levels [
33].
The ten-item SPS measured the belief perceptions of participants relating to spiritually-related interactions. Scores above or below the mean respectively represented high and low spiritual involvement. The SPS has consistently been reliable with Cronbach’s alpha above 0.90 [
34].
Analysis
The data gathered from the study were analyzed with the Statistical Package for Social Sciences (SPSS) version 20. Descriptive statistics were used to represent the characteristics of participants. Anxiety, depression and stress, and medication adherence as well as the level of spirituality were evaluated using chi-square tests and logistic regression models.
Ethics
Ethical clearance from the institutional ethics committees for KBTH and KATH were obtained before conducting the study. The ethical approval codes are NMIMR-IRB CPN 044/10-11and CHRPE/AP/022/12 respectively.
Conclusions
Patients with hypertension manifested symptoms of anxiety, depression and stress. This implies that the patient’s hypertensive state and perhaps the need for adherence to the anti-hypertensive medications placed psychological demands on their health. Thus, although hypertension could be viewed in itself as a biomedical problem, patients’ experiences with the demands of living as hypertensives resulted in mental health problems. This illustrates the link between biomedical problems and the development of psychological disorders. Further, spirituality helped patients cope with the emotional burden of having hypertension; a chronic disease. Therefore, the need to adopt a multi-faceted perspective towards health delivery in Ghana becomes real in the purview of these findings. The involvement of clinicians, pharmacists, clinical/health psychologists, religious leaders, and nurses thus becomes important in alleviating the problem of non-adherence and invariably improving the quality of life outcomes of hypertensive patients. Attention could be directed toward the use of spirituality as a possible mechanism by which negative emotions are managed among hypertensive patients.
Acknowledgements
The authors wish to thank the hypertensive patients who participated in this study as well as the staff of KBTH and KATH. For their technical support, the authors are grateful to Dr. Joseph Osafo and Dr. Asamoah Kusi. This research was partially funded by the African Doctoral Dissertation Research Fellowship offered by the African Population and Health Research Center (APHRC) in partnership with the International Development Research Centre (IDRC) as well as the University of Ghana Faculty Development Grant by Office of Research, Innovation and Development (ORID).
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (
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http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Competing interests
The authors declare that they have no competing interest.
Authors’ contributions
IK was involved with research concept, data collection, data analysis, interpretation of results, and writing of manuscript. FO and SD contributed to the research concept and interpretation of results. All authors reviewed and approved the final manuscript.