"Bridging the gap": development and Delphi consensus validation of a framework for hypertension management in primary healthcare in Kisumu County, Kenya: a mixed methods study

¹Department of Public Health and Community Development, School of Sciences, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya, ²Center for Community Health and Wellbeing, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya

^&Corresponding author
Oscar Okoth, Department of Public Health and Community Development, School of Sciences, Jaramogi Oginga Odinga University of Science and Technology, Bondo, Kenya

Introduction    

Hypertension (HTN) is a major preventable risk factor for cardiovascular diseases (CVDs) and remains a leading cause of death among non-communicable diseases (NCDs) [1]. Globally, an estimated 1.4 billion people are living with HTN, a figure that was projected to rise to 1.6 billion by 2025, with the greatest burden in low-resource settings [2]. Sub-Saharan Africa (SSA) has the highest regional prevalence at 30.8%, with Tanzania and Kenya experiencing the highest rates in the region [3]. In Kenya, HTN prevalence among adults aged 18-69 years is estimated at 24% to 29% [4], while Kisumu County reports a prevalence of 22% [5]. Recognizing the growing burden of HTN, the World Health Organization (WHO) has prioritized strengthening primary healthcare (PHC) for early detection, treatment, and continuity of care. Consequently, global frameworks such as WHO Package of Essential Noncommunicable Disease Interventions (WHO-PEN) and HEARTS technical package have been developed to support HTN management [6,7]. At the national level, these initiatives are mirrored by the Kenya National Strategic Plan for the Prevention and Control of NCDs [8], which seeks to support the integration of NCD services into PHC level. However, despite these frameworks and policy, utilization of HTN management services remains suboptimal resulting in low treatment and control rates in low- and middle-income countries [9,10]. Globally, fewer than 42% of those diagnosed with HTN receive treatment, and only 14% achieve BP control [11]. In SSA, treatment and control rates are 18% and 7%, respectively [10], with Tanzania and Kenya still reporting lower rates [12].

In Kenya, the treatment rate stands at 26.9% and control at 13.7% [13]. In Kisumu County these rates decline further at 6.7% treatment and 3.8% control [5]. Key barriers include low awareness, poor adherence, financial constraints, inadequate provider capacity, drug stockouts, poor availability of services, and limited equipment [14-16]. Additionally, limited availability of data on NCD burden leads to a gross underestimation [17] thus the inability to lobby for investment in NCD care service delivery. In Kenya, the Ministry of Health identified inadequate capacity of the health workforce in terms of numerical strength and skills as additional gaps [8]. While Kenya has successfully leveraged its PHC infrastructure and service delivery models to improve HIV and tuberculosis outcomes, comparable success has not been realized in HTN care. To better understand the contextual factors influencing HTN management at the PHC level, we previously conducted and published a formative cross-sectional mixed-methods study in Kisumu County, Kenya, which assessed PHC facility capacity and identified barriers to HTN management.

Study findings highlighted substantial barriers including limited provider capacity, shortages of medicines and equipment, financial constraints, poor access to services, poor treatment adherence, and low patient awareness [18]. The similarity between the formative study findings and those reported in previous studies from Kisumu County [19] provides contextual validation of the identified barriers, indicating that the challenges are not isolated observations but represent persistent constraints within the PHC system that require sustained intervention. Supplementary data collected as part of the formative study but not reported in the previous publication outlined the potential mitigation strategies proposed by stakeholders to address the identified barriers. Together, these published findings and supplementary data informed the development and subsequent Delphi consensus validation of a context-specific framework for strengthening HTN management in Kisumu County, Kenya. The study adopted Andersen's Behavioral Model of Health Service Utilization [20] to guide the categorization and mapping of barriers to inform alignment with identified strategies.

Overall objective: the overall objective of this study was to develop and achieve expert consensus validation of a context-specific framework for strengthening hypertension management at the primary healthcare (PHC) level in Kisumu County, Kenya.

Specific objectives: the specific objectives were to identify HTN management barriers and potential mitigation strategies using published and supplementary formative findings, develop a context-specific framework to strengthen care, and validate this framework through a modified Delphi process.

Methods     

Study design and setting: phase I involved synthesizing findings from a previously published formative study, including participant-generated recommendations that had not been reported in the primary publication, to identify proposed mitigation strategies for improving HTN management. Phase II involved the development of a context-specific framework for HTN management based on the identified barriers and mitigation strategies through consultative stakeholder meetings. While phase III validated the developed framework using a modified Delphi consensus process. This study was conducted in Kisumu County a region reporting substantial gaps in HTN management and practices [18,19]. For health administrative purposes, the county is divided into seven sub-counties, and each is led by a medical officer of health who is responsible for overseeing health service delivery and management.

Study participants: participants varied across the three study phases. Phase I drew on data from a previously conducted formative study involving 27 primary healthcare facilities, 274 patients with hypertension, 14 healthcare providers, 4 health managers, and 32 community health promoters (CHPs) who participated in focus group discussions. Phase II involved seven sub-county medical officers of health purposively selected based on their leadership and oversight roles in healthcare planning and service delivery. Phase III involved seven purposively selected experts with experience in HTN management, health systems strengthening, health policy, research, and non-communicable disease programming. The expert panel comprised two physicians, two public health specialists, one health policymaker, one medical researcher, and one NCD program specialist.

Phase I: formative study: phase I involved synthesizing qualitative and quantitative findings from a previously published formative study, alongside unpublished supplementary data. These combined sources were reviewed to identify and consolidate proposed mitigation strategies for the identified barriers. Using Andersen's behavioral model of health service utilization, the barriers were classified into predisposing, enabling and need factors. This classification enabled a systematic understanding of barriers across levels of influence and informed the alignment of corresponding mitigation strategies during the framework development.

Phase II: framework development: this phase involved a consultative meeting with seven medical officers of health to developed a framework to support HTN management in Kisumu County. Barriers identified in formative study were translated to a corresponding desired outcome, representing the ideal state needed to improve HTN management. The proposed mitigation strategies were reviewed and refined by comparing them with public health intervention approaches widely recognized for strengthening HIV and tuberculosis (TB) management in resource-constrained settings. The Lisa Wyatt logic model guide [21] was used to organize and link each outcome to specific strategies which contribute to their achievement. Measurable indicators for each outcome were developed with formative study quantitative finding on each barriers adopted as baseline result for future evaluation.

Phase III: framework validation: a structured questionnaire developed from the draft framework during the consultative meeting was used to gather individual experts' opinions on the feasibility of implementing the identified strategies which formed the framework. To maintain consistency, experts were restricted from proposing new strategies and were only allowed to provide feedback on the wording and clarity of the identified strategies. Each strategy was assigned a rating score using a five-point Likert scale (1 = strongly disagree, 2 = disagree, 3 = neutral, 4 = agree, and 5 = strongly agree) and independently assessed by all the experts. Consistent with commonly reported Delphi consensus criteria, strategies were retained when they achieved a mean score of ≥ 4.0 and at least 80% of panelists rated the strategy as either 4 ("agree") or 5 ("strongly agree"). Strategies that failed to meet the rigorous a priori consensus criteria were dropped.

Study variables: the variables were categorized into health system, provider and patient factors, and framework outcome. Health system factors: included availability of HTN services, clinical guidelines, essential medicines and supplies, diagnostic equipment, and staffing capacity; patient factors: included HTN awareness and treatment adherence; provider factor: included training on HTN management and use of clinical guidelines; framework content: included increased improved availability of medicines and equipment, affordable HTN services, improved access to HTN care, enhanced healthcare worker capacity for HTN management, improved treatment adherence and increased awareness and early diagnosis of hypertension; validation outcomes: included percentage of strategies that achieved consensus.

Data collection: the formative study was conducted between December 2023 and February 2024. A draft framework was developed in December 2024 and refined for validation in January 2025, while the expert consensus validation of the framework was conducted in January 2025 for the first round and second round in February 2025. Experts returned their questionnaires via email and were printed for data entry.

Validity and reliability: the framework's validity was strengthened through triangulation of formative study findings, stakeholder recommendations, and evidence-based public health interventions. The Delphi validation questionnaire comprised items assessing the relevance, feasibility, and appropriateness of the proposed framework strategies across the six identified barrier domains. Internal consistency of the questionnaire was assessed using Cronbach's alpha based on experts' responses to all questionnaire items in round 1, yielding an acceptable reliability coefficient (α = 0.70). This indicated satisfactory consistency among the questionnaire items used to assess expert consensus on the framework. Content and face validity were established through the Delphi process involving multidisciplinary experts who evaluated the relevance, clarity, and feasibility of proposed strategies, while reliability of the framework was demonstrated by consistent expert agreement across Delphi rounds, with retained strategies meeting the predefined consensus criteria of a mean score ≥4.0 and ≥80% agreement.

To eliminate design bias, the panel excluded those who participated in the formative study and the framework development phase, and to eliminate peer influence and social desirability bias, the Delphi survey rounds were administered independently via email, and panelists remained entirely blinded to the identities and specific scoring profiles of the other participants.

Data analysis: in phase I, data synthesis from the formative study was conducted narratively, for supplementary data frequency and percentage were computed for quantitative findings while qualitative data underwent thematic analysis. In the second phase, a logical model guide for better strategies, was used to link desired outcomes with corresponding mitigation strategies. In the third phase, quantitative analysis involved calculating mean rating score and percentage agreement threshold for each strategy. The mean scores and percentage agreement were used to assess the level of expert agreement and prioritize strategies for inclusion in the subsequent round of validation and final framework. Strategies that achieved consensus were reported as percentages of all items subjected for validation. SPSS v23 was used to analyze quantitative data, while qualitative data underwent thematic analysis in NVivo.

Ethical consideration: ethical approval for the study was obtained from Institutional Ethics and Review Committee of Jaramogi Oginga Odinga University of Science and Technology (ERC 39/09/23-41), a license from National Commission for Science, Technology and Innovation (NACOSTI/P/23/30384) and authority to access facilities granted by Kisumu County Department of Health (Ref: GN 133 Vol. XL 009). The approved protocol covered all study phases, including formative research, framework development consultations with stakeholders, and the two-round modified Delphi consensus validation Written informed consent was obtained from all participants prior to participation.

Results     

All seven targeted sub-county medical officers of health participated in the consultative framework development process, resulting in full representation of all sub-counties within Kisumu County. As senior health managers, they had extensive experience in PHC coordination, facility supervision, NCD service oversight, and implementation of county health policies, providing valuable insights on the feasibility and applicability of the framework. Seven experts participated in the Delphi validation process, including two physicians, two public health specialists, one health policymaker, one researcher, and one NCD program specialist. The mean professional experience of the panel was 31.7 years (range: 25-45 years). All experts completed both Delphi rounds, yielding a response and retention rate of 100%.

Phase I: synthesis of findings from formative study and supplementary data: six major barriers to HTN management were identified at the primary healthcare level in Kisumu County. Patient-level barriers included low awareness of HTN and its management (predisposing factor) and poor treatment adherence (need factor). Enabling factors comprised provider level barrier which included limited healthcare worker capacity, and health system level barriers including shortages of medicines and equipment, financial constraints, and poor access to services. Review and consolidation of supplementary data identified 43 raw, potential mitigation strategies for supporting HTN management. Findings from this phase informed the framework development phase.

Phase II: development of the hypertension management framework: the six identified barriers in phase one were translated into six desired outcomes representing the ideal state needed to improve HTN management and informed the framework design. Health system-level barriers informed outcomes related to improved availability of essential medicines and diagnostic equipment, increased affordability of HTN services, and enhanced access to HTN care. The provider-level barrier informed the outcome of strengthening healthcare worker capacity for HTN management, while patient-level barriers informed outcomes related to improved treatment adherence and increased awareness and early detection of HTN. The 43 strategies were subsequently reviewed against established public health approaches that have demonstrated effectiveness in HIV and tuberculosis programs Following consolidation and adaptation to the local HTN management context, 37 strategies were retained and aligned with the corresponding framework outcomes they were intended to achieve.

The strategies were distributed across the six outcomes, with 16 strategies supporting patients level outcome, 7 strengthening healthcare worker capacity, and 14 supporting health system level outcomes. Seventeen indicators were developed to monitor progress across the six outcomes during implementation. Increased awareness and early diagnosis of HTN and strengthened healthcare worker capacity both had 4 monitoring indicators. Improved availability of essential medicines and diagnostic equipment had 3 indicators, while improved treatment adherence, increased affordability of HTN services, and enhanced access to care all had 2 indicators. The findings generated during the formative study were incorporated into the framework as baseline values against which progress toward each of the six outcomes can be assessed. At the time of framework development, awareness and early diagnosis stood at 49%, treatment adherence at 41%, provider capacity for HTN management at 24%, affordability of HTN care at 26%, and both availability of essential medicines and equipment and access to HTN services at 15%. These baseline measures are intended to serve as benchmarks for evaluating framework implementation and effectiveness.

Phase III: framework validation: in the first round of the Delphi process, 34 of the 37 strategies (91.9%) achieved the predefined consensus threshold, indicating a high level of agreement among experts regarding their relevance and feasibility for implementation within the local health system context. Three strategies did not reach consensus and were dropped. These included installation of BP machines in public places, allocation of specific clinic days for HTN services and referral of patients to facility of choice due to financial challenges. Experts' feedback considered them less practical, sustainable and not integrated within existing PHC service delivery model and referral mechanism.

The second Delphi round reassessed the 34 strategies retained from round 1. Overall, 30 of the 37 strategies initially subjected to Delphi validation achieved expert consensus and were retained in the final framework, corresponding to an overall retention rate of 81.1%. Four strategies failed to maintain consensus and were dropped: individual BP monitoring at home, training CHPs to deliver medicines at home, free drugs during medical outreaches to reduce financial burden and mobilizing partner support for HTN care. Expert feedback highlighted concerns regarding the quality assurance and oversight of home BP monitoring and medicine delivery by CHPs. Additional concerns were raised about the long-term financial sustainability of free drugs during outreaches and reliance on external partners to support HTN care. Analysis of the ratings for strategies that achieved consensus across both rounds demonstrated minimal variability, indicating strong convergence of expert opinion and stability of consensus. Consequently, two Delphi rounds were considered sufficient for the framework validation. The validation outcomes for each Delphi round and the final decisions regarding the proposed strategies are summarized in Table 1, while architectural overview of the framework development process, including the key findings generated at each phase is illustrated in Figure 1.

The final framework comprised 30 validated strategies linked to six outcomes with 17 monitoring indicators. Of the validated strategies, 5 support awareness and early diagnosis, 8 treatment adherence, 6 strengthening healthcare worker capacity, 7 improving the availability of medicines and equipment, 2 increasing affordability of HTN services, and 2 enhancing access to HTN care as shown in Table 2. The interaction of strategies across health system, provider, and patient levels, creating a coordinated multilevel approach for HTN management and improves utilization of services at the primary healthcare level as illustrated in Figure 2.

Discussion     

This study developed framework provides a comprehensive and context-specific approach to improving HTN service utilization at the PHC level by addressing patient-, provider-and health system-level barriers simultaneously. A key strength of the framework is its adaptation of strategies that have demonstrated effectiveness in strengthening management of communicable diseases. This highlights opportunities to leverage existing PHC infrastructure and implementation experience from communicable diseases to strengthen HTN care. The use of the Lisa Wyatt logic model [20] further strengthened the framework development by clarifying the pathways through which the proposed interventions are expected to address identified barriers and improve HTN outcomes.

Community awareness and early detection emerged with 5 intervention strategies, reflecting the substantial contribution of low awareness and delayed diagnosis to poor HTN clinical outcomes, as reported [21-23]. Consequently, the framework emphasizes community sensitization, routine health education, use of IEC materials, and BP screening at both facility and community levels. These interventions have the potential to promote early diagnosis and timely linkage to care, which are critical for preventing hypertension-related complications [24,25].

Treatment adherence emerged as the highest priority intervention area in the framework with 8 strategies. Strategies such as defaulter tracing, family engagement, psychosocial support groups, and reminder SMS messages addresses key barriers to long-term treatment adherence [26-28] Similar approaches have been effective in improving retention and treatment outcomes in HIV programs [29,30], suggesting their potential relevance for HTN management.

The framework further recognizes that high-quality HTN care depends on adequately trained healthcare providers and reliable availability of medicines, and diagnostics equipment. Provider capacity strengthening strategies, including training, mentorship, supportive supervision and use of clinical guidelines, have been successfully implemented in other health programs and shown to improve provider competence, quality of care and patient outcomes [31], while mechanism to improved medicine procurement and availability support treatment continuity, sustainability and long-term patient outcomes [32].

Despite strategies aiming to improve affordability of HTN services being less than awareness and adherence, they remain important determinants of HTN healthcare utilization. Strengthening medicine supply including facility-level purchasing may reduce treatment interruptions and out-of-pocket expenditures, thereby improving access to long-term care [26]. Similarly, medical outreaches in hard-to-reach areas and strengthening facility capacity to provide comprehensive HTN services may improve access and reduce geographical inequities in service delivery [33,34].

Although the framework demonstrate substantial alignment with WHO PEN and HEARTS [8,9] in enhancing provider capacity, access to essential medicines and diagnostics, use of standardized protocol, health education, and service delivery, it differs by focusing only on locally prioritized components. Unlike the global frameworks, team-based care and monitoring systems were not included because they are not identified as key challenges to HTN management in Kisumu County. Beyond informing implementation, the framework provides county health managers with an evidence-based tool for advocacy, planning, and resource mobilization, including engagement with the County leadership to support dedicated NCD financing.

Strengths and limitations: the scientific approach employed in the development of this framework enhances credibility, relevance and potential applicability to Kisumu County and other similar resource-constrained PHC settings. However, the development and validation of the framework was within a single county this limits its transferability. Secondly, although the Delphi process enabled expert validation of the framework, the relatively small expert panel may have limited the diversity of perspectives. Thirdly, the purposive sampling approach used in participant selection may have introduced selection bias.

Conclusion     

A context-specific framework comprising 30 validated strategies was developed to address key barriers to HTN management at the primary healthcare level. Its application may support ongoing efforts to strengthen PHC system and advance prevention and control of NCDs in Kenya and similar resource-constrained settings. Further studies should evaluate its effectiveness, scalability, and cost-effectiveness.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Oscar Okoth: led research conceptualization, data collection, analysis, and manuscript writing; Amos Ochieng Otedo: offered expert advice on study design and assisted in refining research questions ensuring relevance of the study's findings to HTN management; George Ayodo: provided guidance on research methodology, data analysis, and interpretation of results, and manuscript development. All the authors read and approved the final version of this manuscript.

Acknowledgments     

Gratitude to the data collection team led by Mrs. Beldina Sigar Onyango and all individuals who contributed to the completion of this manuscript.

Tables and figures     

Table 1: validation results and expert Delphi ratings for the hypertension management framework, January-February 2025

Table 2: operational log frame matrix and baseline indicators for the primary healthcare hypertension management framework, study done between December 2024-February 2025

Figure 1: architectural flowchart of the sequential multi-phase development and validation pathway of the framework, December 2024

Figure 2: structural model illustrating the multi-level variable interactions and operational pathways of the validated framework, February 2025

References