Managing hypertension in rural Gambia and Kenya: Protocol for a qualitative study exploring the experiences of patients, health care workers, and decision-makers

Background Hypertension is the single leading risk factor for premature death in Sub-Saharan Africa (SSA). Prevalence is high, but awareness, treatment, and control are low. Community-centred interventions show promise for effective hypertension management, but embedding such interventions sustainably requires a good understanding of the wider context within which they are being introduced. This study aims to conduct a systematic health system assessment exploring the micro (patients/carers), meso (health care workers and facilities), and macro (broader system) contexts in rural Gambia and Kenya. Methods This study will utilise various qualitative approaches. We will conduct (i) focus group discussions with people living with hypertensive to map a ‘typical’ patient journey through health systems, and (ii) in-depth interviews with patients and family carers, health care workers, decision-makers, and NCD partners to explore their experiences of managing hypertension and assess the capacity and readiness of the health systems to strengthen hypertension management. We will also review national guidelines and policy documents to map the organisation of services and guidance on hypertension management. We will use thematic analysis to analyse data, guided by the cumulative complexity model, and theories of organisational readiness and dissemination of innovations. Expected findings This study will describe the current context for the management of hypertension from the perspective of those involved in seeking (patients), delivering (health care workers) and overseeing (decision-makers) health services in rural Gambia and Kenya. It will juxtapose what should be happening according to health system guidance and what is happening in practice, drawing on the experiences of study participants. It will outline the various barriers to and facilitators of hypertension management, as perceived by patients, providers, and decision-makers, and the conditions that would need to be in place for effective and sustainable implementation of a community-centred intervention to improve the management of hypertension in rural settings.

depth interviews with patients and family carers, health care workers, decision-makers, and NCD partners to explore their experiences of managing hypertension and assess the capacity and readiness of the health systems to strengthen hypertension management.We will also review national guidelines and policy documents to map the organisation of services and guidance on hypertension management.We will use thematic analysis to analyse data, guided by the cumulative complexity model, and theories of organisational readiness and dissemination of innovations.

Expected findings
This study will describe the current context for the management of hypertension from the perspective of those involved in seeking (patients), delivering (health care workers) and overseeing (decisionmakers) health services in rural Gambia and Kenya.It will juxtapose what should be happening according to health system guidance and what is happening in practice, drawing on the experiences of study participants.It will outline the various barriers to and facilitators of hypertension management, as perceived by patients, providers, and decision-makers, and the conditions that would need to be in place for effective and sustainable implementation of a community-centred intervention to improve the management of hypertension in rural settings.

Introduction
Hypertension is a major cause of premature mortality, accounting for an estimated 10.7 million deaths globally 1 .Sub-Saharan Africa (SSA) has the highest burdens, with prevalence rates at around 30% 2 , and in this region, hypertension was implicated in about 1 million deaths in 2019, double the number in 1990 3 .
The high burden of hypertension poses significant challenges to health systems in SSA where a high proportion of the population with hypertension remains unaware, undiagnosed, and inadequately or not treated 4,5 .It has been estimated that 73% of people with hypertension in SSA do not know about their hypertensive status, 82% of those with hypertension are not receiving treatment, and 93% do not have their blood pressure controlled 5 .Poorly controlled hypertension is associated with high levels of disability, productivity losses and major socioeconomic costs, exacerbating poverty and increasing health inequalities 6,7 .This is a particular concern for rural areas, where health systems are generally weak and case-fatality for cardiovascular diseases is high 8 .
There is an urgent need to reduce the hypertension-related burden in SSA through effective control along the care pathway; from early detection to timely effective management 9 .However, there are multiple and complex barriers to achieving this.At the individual level, these include the asymptomatic nature of hypertension, lack of understanding of its potentially serious consequences and competing priorities around home and work, making people only seek care when they experience complications [10][11][12][13][14] .Such barriers are compounded by misconceptions about aetiology and the potential benefits of pharmacotherapy 13 , which, along with an inability to afford medication, can lead to poor treatment adherence.At the health care worker level, poor communication, lack of skills and competencies, limited number of trained health workers, and inadequate referral systems complicate optimal treatment [15][16][17][18][19][20] .System-level barriers include poor access to health facilities, particularly in rural areas, unreliable supply of antihypertensive medications, poor coverage of national health insurance schemes, and underinvestment in health service infrastructure 16,19,[21][22][23] .
Growing evidence points to the benefits of multifaceted, community-centred interventions involving community health volunteers (CHW) to control non-communicable diseases (NCDs) like hypertension more effectively in resource-constrained settings 24,25 .Such interventions were found to be especially promising in rural and remote settings, where access to health facilities is poor [26][27][28][29][30][31] .However, there remain questions about the sustainability and scalability of such programmes, especially where disease burdens are high, but the capacity to effectively address NCDs is low.This requires a deep understanding of the wider context within which interventions are being implemented.Context includes the existing policies, organisational, and institutional structures.Context also includes how people using (patients and their family carers), delivering (health care workers) and overseeing services and structures (decision makers at the different system tiers) understand and experience existing approaches to NCD management, and what changes that introducing a novel intervention will mean for them.Such understanding will be necessary to ensure the acceptability, feasibility, sustainability, and scalability of new service models.
This study is part of a larger project, the National Institute of Health Research (NIHR) Group for Improving Hypertension Control in Rural Sub-Saharan Africa (ICHoR-Africa) 32 that seeks to develop and evaluate the feasibility of a communitycentred approach to improve the management of people with hypertension in rural Africa.This study will systematically assess the micro (patients/carers), meso (health care workers and facilities) and macro (broader systems) contexts in rural Gambia and Kenya by exploring how people living with hypertension understand and manage their conditions and the perspectives and experiences of those organising, financing, and delivering hypertension care services.It will provide important insights into the perceived and experienced barriers to seeking (people with hypertension) and delivering (health care workers, decision-makers) effective hypertension management and how these can be addressed to inform the development and implementation of a community-centred hypertension management intervention in rural SSA.

Study aims and objectives
The overarching aim of this study is to understand the experiences, needs, and practices at the individual, organisational, and system levels to detect, treat, and control hypertension in rural Gambia and Kenya.The specific objectives are to: 1. Map a typical journey that someone with hypertension will undertake in each setting and contrast what should happen at the different stages of the journey and what happens in practice.
2. Explore the experiences of people involved in using (patients and their family carers), delivering (health care workers) and overseeing services and structures (decision makers at the different system tiers) for hypertension management.
3. Assess the health services delivery context, including policy and guidelines within which hypertension care is provided.
4. Examine the health system's capacity and readiness for strengthening the management of hypertension at the different levels of the health system.

Amendments from Version 2
We clarify in the paper the type of phenomenological approach that we used to develop topic guides for data collection.We also clarify how data from both Gambia and Kenya will be analysed and utilised to inform the development of a community-based intervention in each country.Such details are provided to reflect the comments made by reviewer 2.
Any further responses from the reviewers can be found at the end of the article

Methods
This is a qualitative study that will use (i) focus group discussion with people living with hypertension and (ii) in-depth interviews with people living with hypertension and their family carers, community health volunteers, health care professionals, decision-makers, and NCD partners in The Gambia and Kenya.We will also review policy documents, guidelines, and standard operating procedures related to hypertension management in both countries.The study period is from August 2022 to April 2024.

Patient and Public Involvement
Community members and stakeholders have been involved in different stages of developing the IHCoR-Africa study project and its implementation.In the Gambia, this included community health volunteers, managers of health facilities, and representatives of the regional health directorates and the Ministry of Health.In Kenya, this included representatives of community advisory groups, community health volunteers, facility managers, county health managers, Ministry of Health representatives, and NCD partners.We held consultative meetings to discuss the research ideas with members of the community advisory board in Kilifi (Kenya) prior to submitting the study proposal for funding.When funding was granted, planned studies were discussed with various stakeholders at different levels in both countries and their feedback was incorporated into the study protocols before seeking scientific and ethical approvals.Upon securing the necessary approvals implementation of the study activities involved community members and sub-national and national health authorities.In both countries, community members are actively involved in sensitisation and consenting of study participants.The findings of this study will also be discussed with community members and stakeholders for validation during meetings.Furthermore, dissemination workshops will be organised at different levels in both countries.

Conceptual framing
Our overall approach to this study places people with hypertension (and their family carers) at the centre of the hypertension care pathway.It recognises that availability of, and access to services that are necessary for successful hypertension management while noting that the social and economic contexts within which people live greatly impact their capacity to seek care and self-manage their conditions.This creates a 'treatment burden' interacting with and complicating clinical care 33 .High burdens will likely result in poorer health care outcomes for individuals.Our analytical approach will be guided by the Cumulative Complexity Model (CCM) 34 .
The CCM distinguishes the demands placed upon people with chronic health problems to (self-) manage their conditions alongside other daily tasks that are associated with living with a chronic disease.This involves users having to engage with health services ('patient workload') and the capacity of health facilities to meet patients' needs given their physical and mental well-being, levels of literacy and beliefs, and importantly, their wider social and economic environment and resources available to them ('patient capacity').Patient workload and capacity are dynamic and interact; an imbalance between these will create compounded risks in care-seeking (e.g., low adherence to treatment) and outcomes (such as complications).
Emerging evidence drawing on this model in SSA found how clinical and social factors accumulate and interact to complicate care for people with chronic conditions [35][36][37][38] .
We will also draw on components of implementation research, in particular theories of organisational readiness and the dissemination of innovations 39,40 .This will enable us to understand the motivations for and capacity to implement the changes required at the organisational and system levels to improve hypertension management in rural Kenya and Gambia.

Settings
This study will be conducted in the Lower River Region of the Gambia (West Africa) and in Kilifi County in Kenya (East Africa).Both settings have high levels of hypertension, estimated to range from 18.3%-32.4% in The Gambia 41 and 12.6-36.9% in Kenya 42 .Documented prevalence rates are likely to be underestimated with data from The Gambia suggesting that almost 70% of those with hypertension may be undiagnosed 43 .Treatment and control rates are low; for example, in The Gambia, in 2018, an estimated 32.5% of hypertensive patients were on treatment and only 10% had their BP controlled 44 .In Kilifi County, only 3% of those diagnosed have their BP controlled 45 .
Both settings have a well-developed research infrastructure which is critical for the overall project activities: Medical Research Council (MRC) Unit The Gambia at LSHTM in Kiang West, and KEMRI Wellcome Trust Research Programme (KWTRP) in Kilifi.
The Gambia.The Gambian operates a three-tier system for the delivery of public health services.The primary level (village health services) is the first point of contact and is run by two community health volunteers, village health workers (VHW) and community birth companions (CBC) 46 .Some communities also have a community clinic run by community health nurses (CHN) or a minor health centre, providing a wider range of services to people who cannot be managed by the VHWs/CBCs 46 .The secondary level comprises (i) major health centres that receive patients on referral from community clinics and minor health centres 46 and (ii) district hospitals which are referral points for minor and major health centres; they offer comprehensive emergency obstetric and surgery services including caesarean section and blood transfusion.The tertiary level consists of thegeneral, teaching and, specialised hospitals; teaching and specialised hospitals are the highest level of the referral system.District hospitals are supervised by the Regional Health Directorate, whereas general and teaching hospitals are semi-autonomous 46 .
The population of the Lower River Region was estimated at 89,157 in 2020 47 .It is mainly rural, with high levels of poverty, at around 60% in 2020 48 .Health services are provided by 13 public health facilities, including 7 community clinics, 5 minor health centres and one district hospital.Facility staffing (skilled health workers) is at 1.54/1000 population, slightly higher than the national average at 1.53/1000 population 47 but significantly lower than the WHO recommended standard of 4.45/1000 49 .
Kenya.The delivery of public health services in Kenya is organised in six levels: community health services (level 1), primary care services provided by dispensaries (level 2) and health centres (level 3), primary referral hospitals (level 4), secondary referral hospitals (level 5) and tertiary (national) referral hospitals (level 6) that provide highly specialised services including specialist medical care, laboratory support, blood product services, and research 50,51 .In Kenya, health facility staffing is at 3.01/1,000 individuals 52 , which is lower than the WHO recommendation of 4.45/1,000 49 .
Kilifi County has a population of about 1.4 million (2019) 53 .
Mainly rural, with main economic activities being subsistence farming, fishing, and tourism 54 , Kilifi is among the poorest counties in Kenya, with around half of the population unable to afford the basic basket of goods in 2021 55 .Health care services in Kilifi County are provided by 150 public health facilities, including 132 dispensaries, 9 health centres, and 9 primary referral hospitals 56 .The County has a total of 1,522 health care workers as of December 2022, with 5.96 skilled health workers per 10,000 people 52,57 .

Data collection methods
The following data collection methods will be used: in-depth interviews with patients, health care workers, decision-makers and NCD partners, focus group discussions with patients, and document review.Different data types will contribute to different objectives.

Focus group discussions (FGD) (Objective 1).
Focus group discussions (FGD) aim to understand how people living with hypertension interact with health care services, from the point of symptom recognition, screening, and diagnosis to ongoing treatment.This first step will allow us to generate a mapping of the hypertension patient journey, assuming a 'typical patient', but noting important variations or divergences as well as gaps in the journey where necessary.It will inform work for Objectives 2-4, and a detailed explanatory analysis, which will be important in understanding points of variation in the journey, major overlaps and gaps as well as giving insights into how the journey is experienced.

In-depth interviews (IDI) (Objectives 2-4
).We will use in-depth interviews to enable a detailed understanding of the views and experiences of those living with hypertension (Objective 2) and of those providing and/or overseeing care for people with hypertension (Objective 3) as well as exploration of the readiness for and capacity of health facilities to introduce new ways of working to improve hypertension management in the two study settings (Objective 4).In-depth interviews provide a suitable approach to engage with people's accounts of their experiences and help understand the context (home, family, work) in which study participants deal with issues related to their health condition.This approach will generate data on how patients pass through the health care system and the challenges they encounter along the care pathway, from the service user, provider, and decision-maker perspectives, for managing their hypertension, access to and use of services, treatment adherence, and patients' and health care workers' preferences for care.

Document review (Objectives 1 and 3).
The document review aims to map service delivery structures, policies and frameworks and the journey of patients with hypertension through health care system in both countries.We will review (i) the principal organisation of the service delivery structures in Kilifi (Kenya) and Lower River Region (The Gambia), including current strategies for and approaches to referral generally and (ii) national/local level guidance on hypertension screening, diagnosis, and management specifically.We will analyse published and unpublished documents including national-level strategy and policy documents, hypertension guidelines issued by professional associations, local standard operating procedures, and other relevant documentation in each study site.Documents will be identified through targeted searches of the websites of governmental and non-governmental agencies and organisations with a remit in health service and system organisation, financing, and governance, and NCDs specifically, including Departments of Ministry of Health in both countries, The Gambia Alcohol Policy Alliance, Pan African Society of Cardiology, the Kenya Cardiac Society, and the NCD Alliance of Kenya.These organisations are project partners; we will consult with them directly to identify any additional information that is not in the public domain.We will also conduct Google Scholar searches to identify any additional documents of relevance to the study aim using the following search terms "guideline/s or protocol", "hypertension", "diagnosis", "treatment", "control" and "sub-Sahara/n Africa".Furthermore, we will approach individual health facilities in the study locations in Kenya and The Gambia to collate clinical protocols and standard operating procedures relating to the management of hypertension where these are available.For the purposes of this study, we understand 'management' to encompass the diagnosis and treatment of hypertension We will use a template to extract data from the included documents for the analysis.

Data collection
Recruitment of FGD and interview participants.We will use a combination of purposive and snowball sampling to identify FGD (people with hypertension and their family carers) and interview participants (people with hypertension/carers, health care workers involved in the delivery of hypertension care, community health volunteers, and decision-makers).
Patients.We will recruit a range of patients from different socio-demographic backgrounds, their location in the patient journey (newly diagnosed, commenced treatment, with complications, drop out, etc.), as well as geographic location (distance to health facilities).For both focus group discussions and in-depth interviews, patients will be identified through the following ways.
i) we will use an opportunistic sampling approach by visiting health facilities on hypertension clinic days (Kenya only; health facilities in The Gambia study site do not operate disease-specific clinic days).People with hypertension visiting the facility on that day will be contacted for participation in the study.
ii) We will work with village health workers (VHW) in The Gambia or community health promoters (CHP) in Kenya to identify and approach patients with hypertension.VHW/CHP are appointed by their local community members and work with them as health volunteers.
iii) We will snowball from patients who have agreed to participate in our data collection.
Health care workers.We will recruit a purposive sample of health care workers involved in the diagnosis, treatment, and control of hypertension across the different levels of service delivery, including physicians, clinical officers, nurses, and community health volunteers in both study settings.
In The Gambia (Lower River Region), we will invite health care workers involved in hypertension management at village health services, community clinics and minor health centres (level 1), and the district hospital (level 2).In Kenya (Kilifi), we will consider all levels of health service delivery, including community health services (level 1), dispensaries (level 2), health centres (level 3), as well as sub-county and county hospitals (levels 4 and 5).
In both study sites, the selection of facilities to be included in the study will be discussed with the relevant health authorities (Gambia Lower River Regional health authorities and Kilifi County health authorities in Kenya) to identify those with active hypertension management clinics.At each level of health facility, the number of health care workers to include in the data collection will be 1-3 individuals.
Decision-makers.These will include those representing the different governance levels in each study site, that is, senior executives (stakeholders involved in NCD/hypertension policy including policy formulation, adoption, implementation, and oversight at national and sub-national levels), managers of health facilities, and members of professional organisations involved in hypertension care programmes.We anticipate that a small number of health care workers identified above will also be facility managers; interviewing them will aim to explore their dual role as both service providers and decision-makers.
The sampling frame for this study is purposive rather than representative.It is intended to capture the range of perspectives of those directly or indirectly involved in hypertension diagnosis and management.Table 1 indicates the sampling for this study.
In total, eight focus group discussions (FGDs) with patients assisted by their adult family carers (where feasible) will be conducted.The overall number of participants for the eight FGDs across the two countries will be 40 -64 individuals, that is, 20 -32 participants in each study site.
Regarding in-depth interviews, we anticipate including 110 -150 participants in total across the two countries, that is, 55 -75 participants in each.Qualitative sample sizes are best determined iteratively when themes generated in interviews approach saturation, based on the judgement and experience of interviewers 58 .Data saturation will be assessed on the basis of whether the study team is not able to identify any new themes after conducting a certain number of consecutive interviews in each category of informants in each study setting.This means that recruitment will stop when data that has been collected is viewed as adequate in relation to the study objectives and that any further data collection will not generate any additional insights.
Therefore, for all participant categories, the final number of informants may vary, which means, we might include a higher or lower number of participants in each category as data collection progresses.This means that additional participants may be identified during data collection who will then be approached for interviews.

FGD and interview process
We developed five topic guides for the different stakeholder groups and interview forms (FGD, IDI) to gain insight into the lived experiences of patients, health care workers, and decision-makers with hypertension care with regard to service use, provision, and oversight, drawing on principles of interpretative phenomenological analysis.This approach enables researchers to move beyond 'surface-level' descriptions of phenomena by offering interpretative accounts of the lived experiences of study participants 59 .This aims to explore what study participants experience in terms of living with hypertension or providing or overseeing hypertension care services delivery and what context or situations have typically influenced or affected such experiences in communities and health facilities 60 .
The development of topic guides for patients was informed by the Cumulative Complexity Model 34 to further explore the experienced burdens of people with chronic diseases such as hypertension in managing their conditions alongside their daily tasks in their communities.The tools further explore people's journey through the system from the first time they were diagnosed, follow-up visits, treatment, and medication, and management of any complications related to their condition to the involvement of community health volunteers in the diagnosis and management of hypertension in their communities.
Topic guides for interviews with village health workers/ community health promoters, health care workers and decision-makers seek to understand their views on the services for hypertension management, including existing treatment protocols and guidelines; experiences of the organisation and delivery of health services for the diagnosis, treatment, and control of hypertension, as well as perceptions of barriers and opportunities to improve current approaches to hypertension care in rural Gambia and Kenya.We also explore perceptions of the capacity and readiness of health systems to improve the delivery of hypertension care.Topic guide development drew on theories of organisational readiness and the dissemination of innovations 39,40 , enabling us to understand how services in both countries may be able to accommodate or implement the changes required at the organisational and system level to improve hypertension management in rural Kenya and Gambia.
An FGD session will convene 5-8 people with hypertension and family carers (depending on the willingness of the patient to be assisted) and will last between 60 to 90 minutes.Four FGDs will be organised in both sites, two FGDs with females and two others with males, in each site.
In-depth interviews will last between 30 to 60 minutes and be carried out face-to-face.
An experienced team in qualitative research will collect data from participants in local languages (Swahili or Giriama in Kenya and Mandinka or Wolof in The Gambia) or in English depending on the participant's language preference.Both in-depth interviews and focus group discussions will take place in a location most convenient for participants.During fieldwork, we will hold review meetings to reflect on our findings and experiences and adjust data collection strategies as needed.

Data analysis
Interviews and focus group discussions will be recorded, with participants' permission, and transcribed verbatim in English.
Transcripts will be imported into the software NVivo 12 for processing and the data will be analysed thematically.
Transcripts will be read repeatedly to familiarise ourselves with the data; data will be inductively coded to develop the coding frame.The resulting coding frame will be applied iteratively across the transcripts and modifications will be made depending on the data, as themes reoccur and appear important about the lived experiences of study participants.These codes will then be grouped into overarching themes, which will be analysed to compare findings across cases.This stage of analysis will involve discussions within the research team to refine the themes and to group them into meaningful conceptual categories.This will allow us to draw tentative conclusions about aspects of the lived experiences of patients with hypertension and their care-seeking from health facilities, experiences and expectations of health care workers and decision-makers about better organisation and delivery of hypertension care in rural settings.The data analysis will further be guided by the Cumulative Complexity Model 34 , organisational readiness, and the dissemination of innovations theories 39,40 as indicated above.Informed consent will be obtained from all participants in this study through their signatures or fingerprints on an informed consent form, in which participants confirm that they have read and understood the project information sheet.Additionally, at the beginning of each interview or FGD, the interviewer/FGD moderator will seek confirmation from participants that they are willing to participate in the data collection and that they agree that the interview and FGD will be audio recorded and transcribed.In case participants are unable to read the information sheet and consent form, these will be read out to them in their native language in the presence of a witness and their consent will be sought and obtained through their signatures or fingerprints on the forms; where a suitable witness cannot be identified, the participant will not be interviewed.After the consenting, a copy of the forms will be given to the participant to keep, and the study team will keep another copy for their record.

Ethical approval
Data collected in each study country will be kept in a secure password-protected environment and any hard copies of interview transcripts and consent forms will be kept in a locked cabinet.Once data have been processed and databases created, they will be encrypted, password-protected and saved on a secured server under each institutional data protection policies, i.e.MRC Gambia (MRCG) and KEMRI-Wellcome Trust Research Programme (KWTRP).Encrypted data from both study sites excluding any personal identifiers will later be transferred to a secure server at LSHTM to be used by researchers across different sites for cross-country analysis.

Dissemination
The findings of this study will inform the development of a community-based intervention in a separate study protocol using a participatory action research approach 61 to be implemented for the diagnosis, treatment, and control of hypertension in rural Gambia and Kenya, as part of the broader IHCoR-Africa research project.Findings and learning will be shared with health care workers, community members, administrative and political stakeholders involved in decision-making about hypertension management policies and guidelines, and members of professional organisations involved in hypertension care programmes through workshops at national and subnational levels.The findings will also be made available on the IHCoR-Africa website.Furthermore, findings will be disseminated via peer-reviewed publications, conferences, media, and lay reports.

Discussion
This study is conducted as part of the broad IHCoR-Africa study that seeks to develop, implement, and evaluate a community-centred intervention to improve hypertension management in rural Gambia and Kenya.Drawing on interpretive phenomenological analysis approach, this study will uncover how individuals living with hypertension understand and interpret their health condition and how they interact with family members and health care providers seeking hypertensive care.It will also provide insight into the experiences of people involved in the delivery and oversight of hypertension care services following health care delivery protocols to juxtapose what should happen and what is happening on the ground when health care providers attend to hypertensive patients in health facilities.This will provide a genuine understanding of different aspects of hypertensive patients' encounters along the care pathway and the system-wide contextual factors from the perspective of hypertension care users, providers, and decision-makers.It will also shed light on the existing organisational structure for diagnosis, treatment, and control of hypertension and how these can be improved to meet the health care needs of hypertensive patients in rural settings.This will significantly contribute to the understanding of barriers to and facilitators of effective hypertension management at individual, health service, and system levels, essential for developing an innovative approach to improve hypertension diagnosis, treatment, and control.Another strength of this study is the analytical framework that it draws on, that is, the organisational readiness and dissemination of innovations theories.This will provide evidence on the capacity and readiness of health systems in both countries to strengthen the management of hypertension at different levels of care delivery and highlight how implementing a community-centred intervention interacts with the broader system.This is essential for ensuring the acceptability, feasibility, sustainability, and scalability of new service models to be delivered and embedded into existing systems for effective hypertension diagnosis, treatment, and control in rural settings.

Study status
Ethics approvals have been secured in both countries and participants' recruitment to the study began in July 2023 as well as data collection.In Kenya, the data collection is ongoing but was completed in The Gambia in October 2023.The transcription of audio files is ongoing in both countries, after which the data analysis will take place.

Conclusions
Using a pragmatic and comprehensive methodological approach, this study will provide insights into the ways health systems in the two countries are ready for change to improve hypertension management.It will also inform the development and implemention of a community-centred intervention and its integration into existing systems in ways that ensure its sustainability and scalability in rural settings.
and joint senior authors.We thank the Gambian and Kenyan health authorities and community stakeholders for their time and guidance provided during the different consultation sessions.We thank the broad IHCoR-Africa that affect the hypertension management.

Olutobi Sanuade
Spencer Fox Eccles School of Medicine at the University of Utah,, Salt Lake, USA I have gone through the revision, and authors have sufficiently addressed all the comments.So, I have no further comments to make.

Is the rationale for, and objectives of, the study clearly described?
Yes

Conceptual framing: ….."to improve hypertension management and control in rural Kenya and
Gambia" How about hypertension detection?Authors need to be clear with the focus of their study-Are they interested in improving hypertension diagnosis, management and control, or only management and control?This inconsistency seems to run through the paper.
○ Data collection methods: Since Kenya and the Gambia operate different healthcare system, how did authors decide the level to choose health care worker participants from in these two countries?I think some statements around this will be helpful to readers.
○ Data collection methods-IDI: "…as well as exploration of the readiness for and capacity of health facilities…."Please which level of health facilities are the authors referring TO here, given that there are different levels and these vary in Kenya and Gambia?
○ Document Review (objectives 1 and 3): "We will analyse published and unpublished documents including national-level strategy…."This approach is different from what was stated in the abstract.Please reconcile this.

Document Review (objectives 1 and 3): " We will also conduct Google scholar searches…"
Please what will the search term focus on?
○ Document Review (objectives 1 and 3): "…and The Gambia to collate clinical protocols and standard operating procedures as they relate to hypertension control" In sub-Saharan Africa, standard operating procedures are usually not written down especially in lower-tier facilities.In such situation, how will the authors obtain the clinical protocols and standard operating procedures?
○ Data collection/health care workers: "In the Gambia (Lower River Region), we will invite health care workers involved in hypertension…."Authors should please provide the number of participants that they intend to recruit from each of these levels of care.
○ FGD and interview process: How criteria do authors plan to use for data saturation?
○ Table 1: Please change "10V15" to "10-15" ○ Ethical approval: "…a copy of the forms a given to the participant to keep".Please change sentence to "a copy of the forms will be given to the participants to keep" ○ Ethical approval: "All data collected for this study will be kept in a secure password-protected environment…."Since data collection will take place at two settings, will the data be stored at ○ a central location or at different sites?Also, what kind of platform do authors plan to use to secure sharing of data across sites?

Conclusions
"….study will advance our understanding of ways health systems…."I think the focus should extend beyond hypertension management but also diagnosis and control.Also, please avoid using possessive pronouns such as "ours" ○ Is the rationale for, and objectives of, the study clearly described?Yes

Are sufficient details of the methods provided to allow replication by others? Partly
Are the datasets clearly presented in a useable and accessible format?

Not applicable
Competing Interests: No competing interests were disclosed.
I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.
workers and facilities) and macro (broader systems) contexts in rural Gambia and Kenya by exploring how people living with hypertension understand and manage their conditions and the perspectives and experiences of those organizing, financing, and delivering hypertension care services.This study is very relevant given the high prevalence of hypertension in sub-Saharan Africa and the potential impact it can have on the population.Understanding ways to enhance hypertension care in SSA is crucial, and this study will offer valuable insights on how to achieve that.While the paper provides valuable insights into the topic at hand, there are areas where improvements can be made to ensure its scientific rigor.Here are some suggestions for enhancing the paper's scientific credibility.

Authors' comment: Thank you for your comment
Reviewer: Abstract: Background: The objective stated here seems to be incomplete.Please ensure that it is the same with the one stated in the introduction section.
Author's response: We acknowledge that the objective provided in the abstract is not as detailed as in the introduction.We are restricted by a word limit, which means that we had to abbreviate the objective in the abstract.

Reviewer:
Methods: Authors should please provide the methods that they intend to use to assess the capacity and readiness of the health systems.
Author's response: This study will not use any standardized assessment tool.We will assess the capacity and readiness of the health systems of both countries based on the accounts from health care providers, decision-makers, and patients by juxtaposing how hypertension should be diagnosed, treated, and controlled as per the national policies and guidelines and what happens in reality in health facilities when health care providers are attending to hypertensive patients, and how the health systems of both countries can be strengthened to offer optimal services for the hypertension care in rural Gambia and Kenya.

Reviewer:
Expected findings: Will this study also be able to describe context for hypertension control since the national guidelines and policy documents will be able to provide this information?Authors need to be consistent as to what the focus of their study will be.Will this study address hypertension diagnosis, management and control, or hypertension diagnosis or diagnosis and management?
Author's response: As set out in the section "Study aims and objectives", our overall aim is to understand the experiences, needs, and practices at the individual, organisational, and system levels to detect, treat, and control hypertension in rural Gambia and Kenya.We recognize that the terminology is not always clear, with the term 'management' taking different meanings in different contexts (e.g., a policy, which would also include primary prevention and a clinical term, that is, reducing blood pressure).Our study specifically focuses on the diagnosis and treatment of hypertension in terms of the processes involved, which ideally lead to an individual's blood pressure being controlled.Altogether, this can be described as 'hypertension management'.We have reviewed the text and clarified the terminology, accordingly, using the term 'management' throughout.We have added a sentence to the Methods section, clarifying that our understanding of 'management' covers diagnosis, treatment, and control, as follows: For the purposes of this study, we understand 'management' to encompass the diagnosis, treatment, and control of hypertension.(p.7 in the revised manuscript)

Reviewer:
Introduction : "Hypertension is a major cause of premature mortality……an estimated 10.7 million deaths globally" Please is this estimate annual estimate?
Authors' response: This was an estimate of the burden of hypertension globally from data generated in 2015.We have amended the sentence to read: Hypertension is a major cause of premature mortality, accounting for an estimated 10.7 million deaths globally in 2015 (1).
Reviewer: "Sub-Saharan African (SSA) has among them highest....." Please edit this sentence for clarity.I will also suggest breaking this into two sentences to improve clarity.

Authors' response:
We apologise for this typological error.We have now revised the sentence to read: Sub-Saharan Africa (SSA) has the highest burdens, with prevalence rates at around 30%, (2) and in this region, hypertension was implicated in about 1 million deaths in 2019, double the number in 1990 (3).

Reviewer:
Methods: "This is a qualitative study that will use focus group discussion and in-depth interviews with people living with hypertension…."The participant focus here is different from what was stated in the abstract.Please reconcile both.
Authors' response: Thank you for your observation, we have amended the wording in both the abstract and the methods section accordingly.The abstract now reads: We will conduct (i) focus group discussions with people living with hypertension to map a 'typical' patient journey through health systems, and (ii) in-depth interviews with patients and family carers, health care workers, decision-makers, and NCD partners to explore their experiences of managing hypertension and assess the capacity and readiness of the health systems to strengthen hypertension management." The introductory sentence to the methods now reads: This is a qualitative study that will use (i) focus group discussion with people living with hypertension and (ii) in-depth interviews with people living with hypertension and their family carers, community health volunteers, health care workers, decision-makers, and NCD partners in The Gambia and Kenya.

Reviewer:
Patient and public involvement: "Community members and stakeholders…."Please provide the list of these stakeholders.

Authors' response:
We have clarified the section as follows: Community members and stakeholders have been involved in different stages of developing the IHCoR-Africa study project and its implementation.In the Gambia, this included community health volunteers, managers of health facilities, and representatives of the regional health directorate and the Ministry of Health.In Kenya, this included representatives of community advisory groups, community health volunteers, facility managers, county health managers, Ministry of Health representatives, and NCD partners.

Reviewer:
Conceptual framing: "Our overall approach to this study….." It seems this sentence is incomplete.Authors should please state what they mean by their approach placing patients at the centre.At the centre of what? policy focus?
Authors' response: We agree and have revised the sentence to read: Our overall approach to this study places people with hypertension (and their family carers) at the centre of the hypertension care pathway.

Reviewer: Conceptual framing: ….."to improve hypertension management and control in rural Kenya and
Gambia" How about hypertension detection?Authors need to be clear with the focus of their study-Are they interested in improving hypertension diagnosis, management and control, or only management and control?This inconsistency seems to run through the paper.

Authors' response:
As noted in our response to an earlier comment, our study focuses on the diagnosis, treatment, and control of hypertension; the term 'management' is also used to refer to these in the document.We have reviewed the entire text to ensure consistency in wording.

Reviewer:
Data collection methods: Since Kenya and the Gambia operate different healthcare system, how did authors decide the level to choose health care worker participants from in these two countries?I think some statements around this will be helpful to readers.
Authors' response: Thank you for your comment.We believe that we have explained our approach in the subsection "Health care workers", within the "Data collection" section, where we detail the level of health facilities and types of health care workers and how these will be identified for inclusion in the data collection.

Reviewer:
Data collection methods-IDI: "…as well as exploration of the readiness for and capacity of health facilities…."Please which level of health facilities are the authors referring TO here, given that there are different levels, and these vary in Kenya and Gambia?
Authors' response: As mentioned in our response to the preceding comment, we provide these details in the subsection "Health care workers" within the "Data collection" section.We describe that we will contact health care workers at different facility levels.Specifically, we note the following (p.8 of the revised manuscript): In The Gambia (Lower River Region), we will invite health care workers involved in hypertension diagnosis and management at village health services, community clinics, and minor health centres (level 1), and the district hospital (level 2).In Kenya (Kilifi), we will consider all levels of health service delivery, including community health services (level 1), dispensaries (level 2), health centres (level 3), as well as sub-county and county hospitals (levels 4 and 5).
In both study sites, the selection of facilities to be included in the study will be discussed with the relevant health authorities (Gambia Lower River Regional health authorities and Kilifi County health authorities in Kenya) to identify those with active hypertension management clinics.At each level of health facility, the number of health care workers to include in the data collection will be 1-3.

Reviewer:
Document Review (objectives 1 and 3): "We will analyse published and unpublished documents including national-level strategy…."This approach is different from what was stated in the abstract.Please reconcile this.
Authors' response: Thank you for raising this point.The information provided in the abstract had, of necessity, to be shortened in line with the word limit requirement of 300 words.We have not changed the text in the abstract for that reason.

Reviewer: Document Review (objectives 1 and 3): " We will also conduct Google scholar searches…"
Please what will the search term focus on?

Authors' response:
We have amended the sentence to read: We will also conduct Google Scholar searches to identify any additional documents of relevance to the study aim, using the following search terms "guideline/s or protocol", "hypertension", "diagnosis", "treatment", "control" and "sub-Sahara/n Africa".

Reviewer:
Document Review (objectives 1 and 3): "…and The Gambia to collate clinical protocols and standard operating procedures as they relate to hypertension control" In sub-Saharan Africa, standard operating procedures are usually not written down especially in lower-tier facilities.In such situation, how will the authors obtain the clinical protocols and standard operating procedures?
Authors' response: Thank you for this important observation.We agree and have amended the sentence to read: Furthermore, we will approach individual health facilities in the study locations in Kenya and The Gambia to collate clinical protocols and standard operating procedures relating to the management of hypertension where these are available.

Reviewer:
Data collection/health care workers: "In the Gambia (Lower River Region), we will invite health care workers involved in hypertension…."Authors should please provide the number of participants that they intend to recruit from each of these levels of care.

Authors' response:
We have added the following sentence: At each level of health facility, the number of health care workers to include in the data collection will be 1-3 individuals.

Reviewer:
FGD and interview process: How criteria do authors plan to use for data saturation?
Authors' response: We do not plan to use a formal numerical approach to determine data saturation (see e.g.Hennink and Kaiser 2022).We have added the following sentences to the "Health care workers" subsection within the "Data collection" section (p. 9 in the revised manuscript): Data saturation will be assessed based on whether the study team is not able to identify any new themes after conducting a certain number of consecutive interviews in each category of informants in each study setting.This means that recruitment will stop when data that has been collected is viewed as adequate in relation to the study objectives and that any further data collection will not generate any additional insights.

Reviewer:
Ethical approval: "…a copy of the forms a given to the participant to keep".Please change sentence to "A copy of the forms will be given to the participants to keep"

Authors' response:
We have corrected the sentence to read: A copy of the forms will be given to the participant to keep, …

Reviewer:
Ethical approval: "All data collected for this study will be kept in a secure password-protected environment…."Since data collection will take place at two settings, will the data be stored at a central location or at different sites?Also, what kind of platform do authors plan to use to secure sharing of data across sites?
Authors' response: We have amended the paragraph to read as follows: Data collected in each study country will be kept in a secure password-protected environment and any hard copies of interview transcripts and consent forms will be kept in a locked cabinet.Once data have been processed and databases created, they will be encrypted, password-protected and saved on a secured server under each institutional data protection policies, i.e.MRC Gambia (MRCG) and KEMRI-Wellcome Trust Research Programme (KWTRP).Encrypted data from both study sites excluding any personal identifiers will later be transferred to a secure server at LSHTM to be used by researchers across different sites for cross-country analysis.

Reviewer:
Conclusions: "….study will advance our understanding of ways health systems…."I think the focus should extend beyond hypertension management but also diagnosis and control.Also, please avoid using possessive pronouns such as "ours" Authors' response: we have amended the sentence to read: "Using a pragmatic and

Is the rationale for, and objectives of, the study clearly described? Yes Is the study design appropriate for the research question? Yes Are sufficient details of the methods provided to allow replication by others? Partly Are the datasets clearly presented in a useable and accessible format? Yes
Please describe if these countries are suitable to analyze together.2. Please describe what "phenomenological enquiry" will be used?
Competing Interests: No competing interests were disclosed.Reviewer Expertise: cardiometabolic disease managementI confirm that I

have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.
Reviewer Report 25 April 2024 https://doi.org/10.3310/nihropenres.14758.r31545© 2024 Sanuade O.This is an open access peer review report distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

the study design appropriate for the research question? Yes Are sufficient details of the methods provided to allow replication by others?
Please edit this sentence for clarity.I will also suggest breaking this into two sentences to improve clarity.This is a qualitative study that will use focus group discussion and in-depth interviews with people living with hypertension…."The participant focus here is different from what was stated in the abstract.Please reconcile both."Our overall approach to this study….." It seems this sentence is incomplete.Authors should please state what they mean by their approach placing patients at the centre.At the centre of what? policy focus?