Community-based care models for arterial hypertension management in non-pregnant adults in sub-Saharan Africa: A scoping review protocol [version 1; peer review: awaiting peer review]

Introduction: Arterial hypertension (aHT) is the most important cardiovascular risk factor (CVRF) in adults living in sub-Saharan Africa (SSA), leading to an excess of cardiovascular disease (CVD) morbidity and mortality. Life-long aHT service delivery models in the region remain mostly anchored to health facilities and are provided by physicians or nurses, thus limiting access to care. Over the past years, decentralized community-based aHT care models have been piloted, aiming to improve access to prevention, diagnosis, and treatment. Although individual studies suggest that community-based care is well-received and potentially efficacious, a synthesized overview of such care models is missing. Hence, the aim of this scoping review is to map out and summarize existing interventions for communitybased aHT diagnosis and care in non-pregnant adults in SSA. Additionally, we will describe outcomes in terms of acceptability, blood pressure control, patient engagement in care, and occurrence of aHT caused end-organ damage. Methods and analysis: We will apply the Arksey and O’Malley scoping review methodology and best practice, as outlined by Levac and the Joanna Briggs Institute scoping review guidelines. The research questions have been identified through a literature review and expert consultation. A systematic literature search will be conducted in four databases using a tailored search strategy, including a supplemental Open Peer Review Reviewer Status AWAITING PEER REVIEW Any reports and responses or comments on the article can be found at the end of the article. Page 1 of 9 F1000Research 2021, 10:487 Last updated: 15 JUL 2021


Background
The sub-Saharan Africa (SSA) region is experiencing an increased burden of non-communicable diseases (NCDs) linked to demographic ageing, rapid urbanization, and the expansion of unhealthy lifestyles, which include sedentarism, unhealthy diet, and tobacco consumption. [1][2][3][4] In this region, cardiovascular diseases (CVDs) heavily contribute to the NCDs burden. 5, 6 CVDs encompass a group of disorders that include coronary heart disease, cerebrovascular disease, peripheral arterial disease, deep vein thrombosis, pulmonary embolism, rheumatic, and congenital heart disease. These conditions add more than 22.9 million disability adjusted life years (DALYs) lost in the region 1 and are a major driver of poverty at the household level in the region due to catastrophic, out-of-pocket expenditure for health care. 7 Arterial hypertension (aHT) is the single most important cardiovascular disease risk factor (CVRF). 8 Yet, efforts focused on the prevention and control of aHT in SSA are limited. As aHT often requires life-long treatment and follow up, patients need to access their health care providers regularly for overall CVDRF control, follow up for potential complications, medication-refill, as well as blood pressure and treatment side effects monitoring. However, these services are mostly provided by physicians, clinical officers or nurses in hospitals, health centres or peripheral clinics. [9][10][11][12][13] Particularly in underserved settings or rural regions, regular attendance to health facilities may be time consuming, expensive, and become a barrier for access or long-term engagement in care. 14 As a result, the aHT cascade of care, defined as awareness, uptake of treatment and adequate control, remains inadequate at individual and population levels. [15][16][17][18] Building on lessons learnt from the global HIV and tuberculosis epidemic responses, service delivery models that promote decentralized, task-shifted, and community-based care could catalyse broader scale-up of quality prevention, diagnosis and care for aHT and other chronic diseases in SSA. [19][20][21][22][23][24][25] However, there is currently no consensus on how such communitybased projects should be designed and if they are able to improve access to high quality care. Therefore, we will conduct a scoping review to describe community-based care models for aHT in SSA, with the aim to summarize the available evidence, discuss their potential for scale up services at community level and to inform future NCD programmes in SSA.

Study objectives and rationale
The primary objective of this scoping review is to describe and construct a framework for categorizing the existing communitybased care models for aHT in non-pregnant adults in the sub-Saharan African region. Secondary objectives include: 1) to appraise the models of care, in terms of acceptability, blood pressure control, engagement in care, and occurrence of end-organ damage, 2) to identify gaps in the literature with respect to community-based service models for aHT, and 3) to describe withinstudy comparisons between community-based and facility-based models of care in terms of outcomes, if provided by authors.
The use of the scoping review methodology will allow us to compile, categorize, and describe the existing use of various community-based health care in the SSA region. It will further identify gaps and priority areas for future research. Additionally, it will provide key information to health professionals and policy makers interested in planning, funding, and delivering interventions to prevent and treat CVDs.
Despite the wide use of the term "community-based" health care models, there is no standard definition of the integrating components. Moreover, implementation of health initiatives at the level of the community in SSA is often diverse and heterogeneous. The definition used for community-based care in this scoping review is adapted pragmatically, including any care model where a substantial part of the care is provided outside formal health care facilities. We will categorize such models in three dimensions: "who provides care in the community?", "how often is care in the community provided?" and "what kind of interventions are included in the community care?" 26 (Table 1).

Methods
This scoping review follows the framework proposed by Arksey and O'Malley 27 which has been further developed by Levac et al. 28 and the Joanna Briggs Institute. 29 We will undertake the following steps: • Stage 1. Identifying the research question.
• Stage 3. Study selection and eligibility criteria.

Stage 1: Identifying the research questions
The key scoping review questions are based on a review of the literature and feedback from subject matter experts guided by the PICO (population, intervention, comparison, outcome) questions ( Table 2). The overarching research question is: what kind of models for community-based care for aHT in adults have been used in SSA, and what are their effects in terms of acceptability, blood pressure control, engagement in care, and occurrence of end-organ damage? Table 1. Community-based care components for arterial hypertension (aHT) to be summarized in this review. CVRF = cardiovascular risk factor.

Target population
• Individuals who are newly diagnosed or already on treatment for aHT What package of care is offered?
At least one (minimum) of the following components is included: • Long-term (chronic care) aHT treatment prescription/distribution • Disease monitoring for treatment success: blood pressure measure, point of care lab tests (urine, creatinine, etc.) • Assessment of aHT end-organ damage categorized as: 1) vascular stroke, 2) retinopathy, 3) coronary heart disease, myocardial infarction, heart failure, 4) nephropathy, including proteinuria, albuminuria, chronic renal insufficiency, and renal failure. The following elements may be part of the model and will be described: • Who provides care?
• Any professional and non-professional cadre • Physicians, non-physician clinicians, nurses, pharmacists (or similar), community health workers (or similar), peers, self-care, psychologists, social workers, or family members • Traditional healers, defined as community members not providing internationally adopted guidelines for aHT care • If non-professional providers: whether the project provides (or not) supervision and training from medical providers Where is care provided?
• Outside of the compound of a permanent health care facility. This may include, but not restricted to, the following settings: outreach services, homebased care, places used for gathering (religious centres, schools, markets, shops) or delivering other services to citizens (pharmacies, etc.). The use of e-Health interventions is also included.
How often are follow up visits?
• Model foresees a reduction in number of patient visits to the health facility, as compared to the standard of care. • Model includes task-sharing with other health cadres and/or self-care.
• The community component is not an "add on" to the care at the facility, but substitutes some of the patient's contacts with health workers at the health facility. Additionally, six secondary research questions have been derived, within the same scope: 1. What are the main components of existing community-based aHT care models?
2. Do existing community-based aHT care models provide an opportunity to offer more user-adapted services in SSA?
3. Can existing community-based aHT care models in SSA expand access to life-long health services for CVDs?
4. How does the quality of aHT care of services provided outside health facilities compare to facility-based care?
5. Are existing community-based care models a solution to decongesting facility-based services?
6. Can non-physician, non-nurse led aHT care provide adequate long-term service quality?

Stage 2: Identifying relevant studies
Based on preliminary searches, the research team and the medical information specialists will jointly formulate the search strategy and search terms. The search strategy will utilise indexed terms and text words. The specific terms will be obtained via analysing titles and abstracts of relevant publications found through preliminary searches and entry terms of relevant indexed terms. The initial search string will be developed for Embase (Elsevier Interface) 30 and translated to search the following electronic databases: Ovid MEDLINE, 31 Cumulative Index to Nursing and Allied Health Literature (CINAHL), 32 and Scopus. 33 We will not apply language limits or date restrictions for peer-reviewed reports. We will also include supplemental search methods of backward and forward citation from included studies to identify other possible articles that meet the inclusion criteria. Conference abstracts will not be considered if they have not resulted in a peerreview publication. The Embase search string is available in Extended data. 39 The search strategy is based on the combination of three concepts: the condition of interest, the components of the care model, and the geographical region ( Figure 1). The search string was developed for scoping community-based care models for hypertension and type-2 diabetes in non-pregnant adults simultaneously. The string related to the components of the care models ("what", "who", "where", "how") included elements described in Extended data, 39 however, terms such as "health programme", "adherence", "medical assistance" where excluded from the string design, as, they increased its complexity and the translation to other databases. The string related to the geographical component was developed based on Campbell et al. 34 and the United Nations standard country or area codes for statistical use. 35 Boolean operators "AND" and "OR" were used to combine search terms. "NOT" was used to exclude terms.
The search string was developed in the database Embase via Elsevier. Macros developed by Erasmus MC information specialists 36 were used to translate the search string to Medline Ovid. The tool SR-Accelerator 37 was used to translate the Medline Ovid search string to Scopus and CINAHL databases. As these tools only correct the syntax to let the string work

Sub-Saharan African region
Communitybased and components of care in the corresponding database, the thesaurus terms had to be adapted manually. Scopus was only searched via text words, as indexed keywords (index terms) are chosen by content suppliers and not uniformly applied.

Stage 3: Study selection and eligibility criteria
Search results from each database will be imported to EndNote X7 and duplicates will be removed, a similar procedure can be done using Zotero. Two independent reviewers will screen the titles and abstracts of all studies initially identified according to the selection criteria to identify relevant studies for full text review. Discrepancies will be resolved by a third reviewer. We will illustrate the study selection process in a PRISMA diagram. Details on studies inclusion and exclusion criteria are detailed in Table 3.

Stage 4: Charting the data
For studies undergoing full text review, a data extraction tool will be created in Word™ (version 2014) and piloted on a subset (n = 3) of studies to determine data validation checks to improve consistency in the data extraction. The data extraction form will include information on the author, year of publication, study design, target population, location of study, duration of follow-up, type of community-care model, health provider cadre, outcomes measured (e.g., acceptability, blood pressure control, etc.), and comparison arm if available. After refining the tool based on the pilot assessment, two reviewers will independently extract the data and review consensus. Data will be stored in Excel™ (version 2014). If consensus cannot be reached, a third reviewer will be involved. We will contact study authors for clarification of methods and other information, as needed. For each article, information on the characteristics of the model of care, and reported outcomes will be tabulated.
Stage 5: Collating, summarising, and reporting results We will report the elements of this scoping review following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) Checklist. 38 We will describe the available data using basic descriptive statistics and narrative synthesis. If interventions (care models) are similar, we will group results by intervention type. Similarly, where possible, we will group and comment on other common features (i.e., health care providing the service, place of delivery and frequency, use of e-Health). We will also summarize each study's outcomes, by study type. Where possible, we will pool outcomes and report average and/or median values, with associated confidence intervals. We will group the studies for features of described care models. Additionally, we will address both quantitative and qualitative gaps in the literature. We will discuss the data in the light of relevant community care models for other chronic conditions (tuberculosis, HIV, diabetes, mental health), propose suggestions for further studies and applications for programmatic scale up.
We will not assess the risk of bias in individual studies, meta-bias(es) (such as publication bias across studies, selective reporting within studies), nor describe the strength of the body of evidence (GRADE).

Stage 6: Stakeholder consultation
A group of experts in the field will be consulted in the process of summarizing results, with the aim of facilitating research translation and dissemination of any recommendations. This includes peer researchers in the same topic and global programmatic and policy stakeholders.

Study status
Currently, the search string has been designed and translated to the search databases. Literature search and deduplication of abstracts is ongoing. Abstracts screening and data abstraction is expected to follow in the following weeks.

Ethics and dissemination
This scoping review summarizes findings from existing publications. It does not involve primary data collection and, as such, does not require ethics review. The results of this review will be of use to public health and medical officials, that are working in the field of NCD care in SSA and similar settings. In that regard, findings will be disseminated through stakeholder meetings, conference presentations, websites, and a peer-reviewed publication.

Time frame
The review is expected to take approximately 9 months.

Data availability
Underlying data No underlying data are associated with this article.
Data are available under the terms of the Creative Commons Zero "No rights reserved" data waiver (CC0 1.0 Public domain dedication).