Determinants of Self-Care and Home-Based Management of Hypertension: An Integrative Review

Introduction: Patients with hypertension should perform diverse self-care activities that incorporate medication adherence and lifestyle modification, such as no smoking or alcohol, weight reduction, a low-salt diet, increased physical activity, increased self-monitoring, and stress reduction, for effective management at home. Aim: This systematic review assessed and synthesized the factors that are associated with self-care and home-based management of hypertension. Methods: The search of the articles incorporated the population, intervention, comparison, and outcome (PICO) framework. The literature was searched in four databases (PubMed, the Cumulative Index to Nursing and Allied Health Literature [CINAHL], Embase, and Web of Science) until 2022. The articles retrieved and searched from the reference list (531) were transported to EndNote version 20, and duplicates (19) were identified and removed to produce 512 titles. Following the eventual title, abstracts, and full-text screening, 13 articles were appropriate for this study. The narrative and thematic data analysis were used to analyze and integrate the data. Results: The analysis showed five themes were associated with home-based self-care and blood pressure (BP) control among patients diagnosed with hypertension. These themes that emerged were (1) the prevalence of control of BP, (2) sociodemographic factors, (3) treatment-related factors, (4) knowledge of management, and (5) knowledge of the prevention of risk factors of hypertension. The demographic factors influencing home-based self-care for hypertension were gender, age, and socioeconomic status. In contrast, the treatment factors were duration of hypertension treatment, medication burden, and medication adherence. Other factors that influenced self-care were inadequate knowledge of BP management, follow-up care, and risk factors of hypertension. Conclusion: Hypertension self-care interventions must incorporate individual, societal, and cultural perspectives in increasing knowledge and improving home-based hypertension management. Therefore, well-designed clinical and community-dwelling interventions should integrate personal, social, and cultural perspectives to improve behavior in the home management of hypertension by increasing knowledge and self-efficacy.


INTRODUCTION
Hypertension disease presents a challenge to patients, as they are expected to institute measures at home to ensure effective self-care and management practices. Patients with hypertension perform diverse activities that can be described as self-care activities for effective disease management [1]. The focus of hypertension self-care management must incorporate medication adherence and lifestyle modification (no smoking or alcohol, weight reduction, low-salt diet, and increased physical activity), increased self-monitoring of blood pressure (BP), and stress reduction [2]. However, self-care management in hypertensive patients must be lifelong, even though it is usually challenging and overwhelming because the patient lacks experience in self-management and the necessary knowledge, tools, and support [3]. Self-care is described as individual actions directed toward self or the environment to regulate individual functioning to improve health, reduce risk, and avoid related complications, as well as ensure general well-being [4,5]. It is important to note that self-care behavior among hypertension patients relates to BP control and prevents related complications [5]. Patient self-care and home-based management of hypertension positively affect clinical outcomes and reduce the occurrence of stroke and related cardiovascular disease [2,5]. Home-based measures are important in the patient's likelihood of avoiding complications and effective improvement [2,4,6]. Self-care adherence is low among adults with hypertension [7] because patients are often unwilling to make recommended behavioral changes [8,9], especially in settings where lay health knowledge is averagely low.
Globally, the prevalence of hypertension has increased and shifted from developed to developing countries over the past 40 years [10]. Nearly three-quarters of hypertensive patients live in developing countries [11]. Awareness of high BP management is deficient in developing countries [12,13]. Many hypertensive patients are ignorant of their disease and treatment due to lack of health care access, distrust of Western medicine, and inadequate health literacy [12,14]. Although adherence to self-care and management is an important part of patient management to achieve hypertension treatment goals, self-care in the African population remains poor [15,16]. Therefore, it is very important to identify factors that influence hypertension self-care and management at home.
The self-care and home management of hypertension, like other chronic diseases, involve various behavioral changes that require optimal and effective medication adherence, self-efficacy, and prevention of complications [6,8,17]. Recent systematic reviews on self-care management of hypertension focused on the use of electronic-based technologies [18,19,20], the influence of self-care efficacy [6], and health promotion interventions for the prevention of hypertension [16,17,21]. However, to the best of our knowledge, no systematic review in recent times has specifically focused on the factors that influence home-based and self-care management of hypertension. This systematic review assessed and thematically synthesized the factors that are associated with self-care and home-based management of hypertension.

STUDY FRAMEWORK
The search of the articles incorporated the population, intervention, comparison, and outcome (PICO) framework. The population was patients diagnosed with hypertension and referred to home care or self-care management. There were no specific comparisons. The outcome was improved hypertension status or a reduction in BP. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework was incorporated in reporting the studies. Using the PRISMA guidelines and checklist allowed for reproducibility, transparency, and clarity in reporting the findings [22,23]. The phases of the entire study included identifying the research question, identifying relevant studies, quality appraisal, and selecting studies for inclusion.

IDENTIFICATION OF THE RESEARCH QUESTION
Home and self-care management of hypertension is an essential factor that can promote the health of people diagnosed with the disease, especially in the poorest parts of the world, like sub-Saharan Africa. Therefore, interventions must be tailored toward addressing the specific determinants of hypertension self-care management. The specific research question was, what are the determinants of self-care and home management of hypertension in low-resource settings in Africa?

QUALITY APPRAISAL
The two authors independently used the Mixed Methods Appraisal Tool (MMAT) version 2018 to assess each study for quality [24,25]. The assessment results using this tool were compared between the two researchers for similarities. Where differences were found between the results from the authors, it was discussed until a consensus was achieved. The MMAT is a quality assessment tool that appraises the methodological quality of qualitative, quantitative, and mixed methods studies. The quantitative section appropriate for appraising the articles selected for this review assessed the aim of the study, study design, methodology, recruitment of study participants, and data collection methods, including analysis, presentation of results, and discussion, as well as the conclusions. Based on the assessment, the studies can be individually rated as high, moderate, or low quality. However, the subsequent views of  emphasized that the researcher does not need to assess the overall quality of studies using this categorization [25]. In their paper, the authors strongly recommended that a detailed presentation of the appraised findings should be done. The components of the screening questions from the MMAT include whether there were (a) the presence of clear research questions and (b) collected data addressing the research question. Based on the consensus gained during the appraisal, all the articles received an affirmative response to the two screening questions above.
The appraisal sections that were relevant for this study were the descriptive quantitative section that assessed the following criteria: (1) relevance of sampling strategy, (2) representativeness of sample to the target population, (3) appropriateness of measurements, (4) risk of nonresponse bias, and (5) appropriateness of statistical analysis. All the studies (n = 11) met the criteria of the appropriateness of the sampling strategy to answer the research question except two studies [26,27]. One study [28] assessed methodological quality using the qualitative section. The results showed an affirmation of all the qualitative appraisal questions. Another study [29] was assessed under the mixed methods section and was also affirmative to all the questions.

RESULTS
Through the advanced search of electronic databases using predetermined keywords (529) and a reference list of identified studies [2], about 531 studies were identified, and 19 were identified as duplicates in the endnotes. The duplicates were removed, and all 512 titles were screened through title and abstract. Based on a predetermined inclusion criterion, 41 studies were full articles, and 13 were identified as appropriate for this study. The process of article selection is shown in Figure 1.

THEMATIC DATA ANALYSIS
The synthesis showed that five key themes were associated with home-based self-care and BP control among patients. These key terms that emerged were (1) the prevalence of control of BP, (2) sociodemographic factors, (3) treatment-related factors, (4) knowledge of management, and (5) knowledge of prevention of risk factors of hypertension. The distribution of key findings is presented in Table 2.

PREVALENCE OF CONTROL OF BP
Two studies specifically assessed the prevalence of hypertension control during their respective studies. It was shown that hypertension control prevalence during the study periods was 47.7% [27] and 37.0% [32].

SOCIODEMOGRAPHIC FACTORS ASSOCIATED WITH BP CONTROL
Several sociodemographic variables were assessed to determine the factors that influence hypertension control. The key subthemes assessed included gender (sex), age, and socioeconomic status.
Gender as a predictor of BP likely to have good self-care practice than males [37]. Also, men were identified to have reduced awareness of BP status [26,39,40]. Men had significantly reduced odds of being aware of their hypertensive status (AOR = 0.35, 95% CI 0.22-0.56) compared to women [40]. Another important predictor was that females had an increased tendency to be adherent to antihypertensive medication use [26,27,34,39]. Females had a higher tendency of BP control behavior, such as weight management (AOR = 0.46, 95% CI 0.23-0.92) and physical activity (AOR = 0.22, 95% CI 0.12-0.40) than males [34]. Females were also identified to have higher medication adherence and BP control [38]. However, some studies did not identify any significant difference in BP control across genders [26,27,33]. Control of BP was not significantly different between men and women [27]. Female respondents were less likely to adhere to physical activity (AOR = 0.51, 95% CI 0.30-0.88) and nonsmoking (AOR = 3.62, 95% CI 1.21-10.85) behavior [33].

Age as a predictor of BP control
The age of hypertension patients was identified as an important predictor of the ability to control BP [32,34,35,36,38,39]. Uncontrolled hypertension was 2.3 times (AOR = 0.19, 95% CI 0.06-0.61) higher among patients above 50 years compared to those above 60 [34]. Also, patients above 50 years were less adherent to weight management than younger individuals (18-35 years) [34]. Self-care practices of participants also improved with advancing age [36]. Patients under 65 years were 3.26 times (AOR = 3.26, 95% CI 1.03-10.35, p = 0.044) more likely to have good self-care practice than patients above 65 years [36]. Also, other studies showed that increasing age was associated with the tendency to be medication adherent and consequently maintain BP control [34,36].

The socioeconomic situation as a predictor of BP control
The socioeconomic status of hypertension patients was an important factor associated with BP control [27,34]. The major economic challenge associated with controlling BP was the medication cost and treatment [27]. The higher medication cost was associated with decreased odds of BP control at the study visit [27]. Odds of control (OR = 0.80, 95% CI 0.70-0.95, p = 0.010) decreased by 20% for every 10,000 Tanzanian shillings (TZS) spent on medication [27]. The place of residence influences the ability of respondents to adhere to medications [34]. Rural residents were less adherent to their medication (AOR = 0.45, 95% CI 0.21-0.97) than urban dwellers [34].
Other factors that predicted BP control and the self-care ability of respondents were the educational levels, as those who had at least a college level of education were found to be 4.205 times (AOR = 4.20, 95% CI 1.30-13.55, p = 0.016) more likely to have good self-care practice than those who were unable to read and write [36]. Participants with greater social support were 2.81 times (AOR = 2.81, 95% CI 1.20-6.53) more likely to adhere to a low-salt diet than their counterparts [33]. Other important socioeconomic factors that predicted control of hypertension were forgetfulness (AOR = 7.90, 95% CI 3.00-20.80, p < 0.001) and lack of finances (AOR = 2.80, 95% CI 1.10-6.90, p = 0.024) [34].

TREATMENT-RELATED FACTORS
The treatment-related factors associated with home-based and self-care management of hypertension had three themes: (1) duration of treatment of hypertension, (2) pill-related factors, and (3) medication adherence.

Duration of treatment
Several important key factors influence the ability to continue treatment and ensure BP control [32,36,37]. Some of these factors included the duration of disease and treatment, significantly influencing the ability to initiate and maintain self-care [36,38] and control BP [32,38]. Less than four years of disease duration was 3.12 times (AOR = 3.12, 95% CI 1.20-8.10, p = 0.019) more likely to practice good self-care than those with less than < 2 years of disease duration [36].

KNOWLEDGE OF PREVENTION OF RISK FACTORS OF HYPERTENSION
Several risk factors of hypertension were identified to influence the tendency to have good BP control. Some of these key risk factors include salt intake, practices, weight control, avoiding smoking and alcohol, and the presence of other comorbidities.
The level of salt in the diet was associated with BP control The level of salt intake was an important predictor of hypertension control among patients, as nonadherents to a low-salt diet were two times (AOR = 1.98, 95% CI 1.18-3.31) more likely to develop uncontrolled hypertension [35]. Also, when individuals', especially women's, knowledge of hypertension was identified to be low, their chances of having a high-salt diet increased [39]. Another important factor was adding salt to meals (OR = 0.40, 95% CI, 0.20-0.60, p = 0.001) as an important factor for BP control [27]. 10 Konlan and Shin Global Heart DOI: 10.5334/gh.1190 Behavioral measures as a predictor of BP control The conscious behavioral measures instituted by individuals were an important predictor of BP control among hypertension patients [27,32,36]. Controlled BP was found 2.7 times (AOR = 2.72, 95% CI 1. 25-5.92, p = 0.011) more associated with good self-care practice than uncontrolled BP [36]. Those who had moderate (OR = 4.80, 95% CI 2.40-9.40, p < 0.001) and good (OR = 11.00, 95% CI 5.00-24.20, p < 0.001) practices to prevent hypertension also had increased odds of controlled BP [27]. More severe hypertension stages, stage II hypertension (OR = 0.17, 95% CI 0.09-0.35) and stage I hypertension (OR = 0.34, 95% CI 0.17-0.67), were associated with more difficulty in achieving the target BP [32].

Weight as a predictor of BP control
Hypertension patients who were more conscious of controlling body weight had a higher chance of BP control [33,35]. The odds (AOR = 2.06, 95% CI 1.31-3.23) of uncontrolled hypertension were twice as high among those with nonadherent weight management [35]. Normal weight patients were 1.82 times (AOR = 1.82, 95% CI 1.07-3.09) more likely to adhere to medication usage practice than overweight respondents [33,35], while normal weight respondents were 2.22 times more likely (AOR = 2.21, 95% CI 1.21-4.04) to practice weight management [33]. Hypertension patients with good self-efficacy were 2.60 times more likely (AOR = 2.58, 95% CI 1.41-4.73) to maintain their weight than poor self-efficacy [33]. Also, rarely or never adhering to normal weight control advice (OR = 0.40, 95% CI 0.20-0.60, p < 0.001) was a predictor of poor hypertension control [27]. Patients who did not adhere to physical exercise were 1.8 times (AOR = 1.79, 95% CI 1.13-2.83) more likely to have uncontrolled hypertension compared to those who adhered to physical exercise [35].

Comorbidities as a predictor of BP control
The level and presence of comorbidities were identified to be associated with hypertension patients' ability to have controlled BP [34,37,39]. Patients with comorbidities were also less adherent to their medication (AOR = 0.16, 95% CI 0.08-0.31) than those without comorbidities [34]. Also, a 69.0% (AOR = 0.31, 95% CI 0.11-0.89) reduction in the odds of having controlled hypertension was identified among patients who suffered from dyslipidemia as a comorbidity [37]. Elevated waist-to-height ratio and diabetes diagnosis were the most significant predictors of hypertension and being aware of hypertension status [39].

DISCUSSION
This review identified and integrated the factors associated with home-based self-care management of hypertension. In chronic diseases like hypertension, home-based management is cardinal in improving a patient's outcome and the ability to avoid complications and limit the progress of the disease [41,42,43]. Hypertension patients must identify and institute home measures that help them improve their BP levels and avoid related complications. The studies on hypertension home-based management are largely cross-sectional and limited to a specific culture or geographical location. Therefore, we were motivated to identify the factors associated with home-based management of hypertension to identify and integrate measures to improve client outcomes. We identified the prevalence of BP control to range from 21.3% [38] to 47.7% [27] among hypertension patients.
This study highlighted the diverse components that must be considered when interventions are implemented for home-based self-care management of hypertension. Hypertension control through self-care at home was reported in similar systematic reviews to be influenced by diverse factors [41]. An important point of this home management involves measuring BP [42,43]. Self-care management of hypertension was instrumental when it was noted that 11 Konlan and Shin Global Heart DOI: 10.5334/gh.1190 intervention efficacy is most felt when the patient is used as the change agent [44]. Poor selfmanagement and medication adherence were identified to negatively influence hypertension control among patients [9].
In this study, we identified multiple interactive factors that influence home-based self-care and management of BP. These factors include sociodemographic, treatment-related, and knowledge of hypertension management and risk factors. Divergent and multiple nature of the factors that are identified to influence hypertension control in Africa warrants commensurate measures to eliminate the associated repercussions of the disease. The culmination of these interventions must focus on reducing hypertension risk, ensuring medication adherence, and promoting appropriate lifestyle modifications.
The divergent factors of multilevel, multicomponent interventions will ensure and promote comprehensive solutions (Mills et al., 2018), especially in lower-and middle-income countries like those in sub-Saharan Africa. This strategy is imperative to limit the challenges imposed by high BP. The sociodemographic factors that influence hypertension control through the homebased self-care ability of patients were gender (female), age (older), place of residence (urban), educational level (educated), and socioeconomic status (high). These sociodemographic characteristics are predictive of hypertension as explanatory variables [16,17,40,45,46,47,48], yet they were identified to influence the ability of patients to control hypertension. While little can be done about sociodemographic factors as a risk to hypertension (nonmodifiable risk), identifying these factors gives a category of where the emphasis should be placed on preventing and controlling hypertension. Home management education must prioritize categories that have inadequate skills in home management. To promote home-based selfcare management of hypertension in lower-and middle-income countries, intervention studies must focus on identifying the influence of each factor on the care of the patient and their ability to institute home-based management of hypertension.
Increasing knowledge on control measures, including limiting risk factors, and improving medication adherence through health education will be central in assisting patients in improving home-based care. In a related systematic review and meta-analysis, this study demonstrated that the number of pills and intake duration strongly influence adherence to medication at home, especially among patients with hypertension [49]. Patients who were noted to take antihypertensive medications over a long period with few medications were said to have higher adherence levels. These factors were important in other systematic reviews [49,50,51]. It is important that when patients are discharged from the hospital to home for selfcare management, only relevant (few) medications with limited pill dosage requirements will promote a positive attitude toward care and ensure hypertension control. It was noted that coordinated interventions used in managing hypertension that limit pill number and frequency among patients and increase knowledge and lifestyle changes are useful [52,53].
Other important themes that emerged were the level of knowledge on hypertension and the presence of risk factors (modifiable risk factors) of hypertension. These modifiable risk factors are mainly centered on knowledge levels, smoking, alcohol, BMI, level of salt intake, and the presence of comorbidities. It was shown that even though this factor predicts the presence of hypertension, it also influences the level of treatment patients adopt during home management. The impact of these modifiable risk factors on the ability to control hypertension, especially in lower-and middle-income countries, was also documented in a previous study [54,55,56]. To improve knowledge and, at the same time, eliminate the risk associated with hypertension, interactive technological methods will increase the likelihood of behavior change, which is implicated in the inability to achieve successful home-based self-care management [12,52].
Research and policy making should streamline intervention studies that will improve homebased and self-care management of hypertension, especially in low-resource settings. In this review, we identified that important interventions that will improve self-care and home management of hypertension should focus on improving self-efficacy, increasing knowledge, and targeting specific attitudes of patients to improve adherence. Also, intervention research methods must focus on eliminating the risk factors of hypertension and segregating patients based on demographic categorization (like age, gender, socioeconomic status, and level of education) for implementation.