Models of integration of HIV and noncommunicable disease care in sub-Saharan Africa: lessons learned and evidence gaps

Abstract

Objective:

To describe available models of HIV and noncommunicable disease (NCD) care integration in sub-Saharan Africa (SSA).

Design:

Narrative review of published articles describing various models of HIV and NCD care integration in SSA.

Results:

We identified five models of care integration across various SSA countries. These were integrated community-based screening for HIV and NCDs in the general population;screening for NCDs and NCD risk factors among HIV patients enrolled in care;integration of HIV and NCD care within clinics;differentiated care for patients with HIV and/or NCDs;and population healthcare for all. We illustrated these models with descriptive case studies highlighting the lessons learned and evidence gaps from the various models.

Conclusion:

Leveraging existing HIV infrastructure for NCD care is feasible with various approaches possible depending on available program capacity. Process and clinical outcomes for existing models of care integration are not yet described but are urgently required to further advise policy decisions on HIV/NCD care integration.

Introduction

Since 2003, significant global investment has facilitated the establishment of HIV care in sub-Saharan Africa (SSA). Consequently, people living with HIV (PLHIV) are living longer, while AIDS-related mortality is declining [1]. Additionally, this infrastructure has strengthened SSA health systems overall through monitoring and evaluation, medications procurement, and task-shifting to provide chronic disease care [2]. As PLHIV initiate and remain on antiretroviral therapy (ART), aging places them at risk of developing noncommunicable diseases (NCDs) [3] compounded by the ongoing epidemiological transition in SSA triggering an increase in NCDs [4–6]. As HIV transitions to a chronic disease, the existing HIV clinical tools, strategies, and systems can be leveraged to tackle NCD prevention and care [7,8]. Innovative models of care responsive to the emerging NCD threat are needed to preserve the attained gains among PLHIV while also informing NCD care for the general population [9].

Prior reviews have described HIV/NCD integration in low-income and middle-income countries (LMICs) [10,11]. We specifically focus on models of care integration in SSA, where HIV prevalence and incidence is highest [12]. Integrated care is defined here as the coordination, co-location, or simultaneous delivery of HIV and NCD services to patients who need it, when they need it [13,14]. Using case studies, we highlight available baseline structures (existing HIV platform) and key added elements (modifications made onto the existing platform) enabling HIV/NCD integration. We also discuss the lessons learned, evidence gaps, and propose a way forward to facilitate efficient HIV/NCD integration.

Methods

We searched PubMed using the keywords ‘HIV’, ‘AIDS’, ‘noncommunicable diseases’, ‘diabetes mellitus’, ‘hypertension’, ‘cervical cancer’, ‘depression’, ‘integration’, ‘leverage’, and their related terms. Eligible studies were included if they described models of integration for HIV/ NCD in SSA across the care continuum. We screened reference lists of retrieved articles to identify additional articles. We did not limit our search by date but we excluded articles that were not in English. For case studies, we sought examples from the retrieved articles which most comprehensively described the implementation process, baseline structures, added elements and outcomes. We also reached out to authors of the articles selected as case studies to elicit updates and seek clarification.

Models of HIV/noncommunicable disease care integration

Five case studies of integrated HIV/NCD models were identified: community-based integrated HIV/NCD screening in the general population, screening for NCDs and their risk factors among PLHIV, integrated care of HIV/NCD in healthcare facilities, differentiated care for stable HIV/NCD, and population health for all patients with any need. These examples are summarized in Table 1 and illustrated in Figure 1.

Table 1.

Case studies for integrated models of care for HIV and noncommunicable diseases in sub-Sahara Africa.

							Screening (S)/Referral
Author, year [ref no]	Country	Disease condition	Population	Brief summary	Highlighted challenges/barriers	Highlighted facilitators/successes	(R)/Care (C)
Case study 1. Integrated HIV and NCD screening and referral
Chamie et al. 2012 [15]	Uganda	HIV, TB, Malaria, DM,  HTN	General population	Community based high-throughput  screening and referral campaign   leveraging HIV testing to include   DM and HTN screening   conducted in a rural district for   4343 persons over 5 days.	Referral to different health  facilities for HIV and NCD  care Insufficient linkage to care rates Low participation by male  gender	Early engagement with local government  and community mobilization efforts  maximized buy in and improved  participation Low incremental cost of leveraging HIV  screening infrastructure for NCD	S & R for both HIV  and NCD
					Participation time long despite  use of POC diagnostics	screening Enhanced referral strategy for HIV patients  with low CD4 led to higher linkage  rates
Case study 2. Screening for NCDs and their risk factors among PLHIV enrolled in care
Kagaruki et al. 2014  [16]	Tanzania	HIV, DM, HTN	PLHIV	Clinic based cross-sectional  evaluation for NCDs and their risk  factors in a cohort of enrolled  PLHIV	Need for a return visit to obtain  fasting blood samples led to  dropouts Low participation by male  gender	Utilizing existing medical personnel to  perform screening required a short  period of training Using local workforce addressed language  barrier concerns	S & R for PLHIV with  NCD or NCD risk  factors
Case study 3. Leveraging HIV platforms to work toward comprehensive primary care in Malawi
Wroe et al. 2015 [17]	Malawi	HIV, TB, DM, HTN,  Asthma, Epilepsy,  Heart failure,  Malnutrition	Patients with any  chronic disease	Implementation of decentralized  integrated chronic care clinics in a  rural district	Initial increase in workload for  nurses following integration Long patient time in clinic of  approximately 2 h	Decentralized care worked to enhance  follow-up Integrated data collection designed to  increase ease of patient management  by minimizing redundancy Clear patient flow and health provider  roles improved efficiency Private-public partnership to supplement  funding for NCD drugs	S & C for HIV and/or  NCD
Patel et al. 2018 [18]	Malawi	HIV, HTN	Stable patients with  HIV	Demonstration project of the  integration on HIV and HTN care  and treatment in HIV service  delivery clinics	Scalability limited by availability  and accessibility of  medications	Evidence-based, standardized protocols Task-shifting Procurement of medications by clinic HTN module for EMRS	S &C for HIV and HTN
Case study 4. Differentiated care for HIV/NCD
Khabala et al. 2015  [19]	Kenya	HIV, DM, HTN	Stable patients with  HIV, DM or HTN	Retrospective evaluation of a cohort  of medication adherence clubs for   stable patients with HIV and/or   NCDs in an urban informal  community	No clinical outcomes described	Daily health talks to patients in clinic led to  voluntary participation in MACs Having time flexibility improved patient  attendance Protocols to standardize care provision  ensured high adherence to nurse led  consultations	C for stable patients  with HIV, HTN or  DM
Case study 5. Population health
Pastakia et al. 2016  [20] Vedanthan et al. 2015  [21] Mercer et al. 2018 [22]	Kenya	All	General population	Integrated population health model  leveraging HIV care infrastructure  in community-based care delivery  through task shifting coupled with  a robust referral network,  electronic medical record system,  supply chain strengthening, food  and income security programs,  and affordable health insurance, to  deliver HIV/NCD and MNCH  services to the Western Kenya  population.	Implementation process  challenges	Widespread consultation with program  partners and key stakeholders to foster  common vision	S, R and C for all

DM, diabetes mellitus; EMRS, electronic medical records system; HTN, hypertension; NCD, noncommunicable disease; PLHIV, people living with HIV; POC, point of care; TB, tuberculosis.

Fig. 1.

Models of care for HIV/NCD integration in sub-Sahara Africa.

Integrated approaches to screening

Screening for HIV has been a key strategy for HIV programs to improve case-finding aimed at ensuring 90% of PLHIV know their status by 2020 [23]. Case-finding has taken on many forms including facility-based, community-based, and home-based screening [24].

Community-based integrated HIV and noncommunicable disease screening and referral

Expanding on existing community-based screening programs, this model provides a multidisease screening package for HIV and NCDs in the general population. Human resources employed in various capacities such as community mobilization, logistics coordination, testing, and counseling is required, with the addition of screening kits for rapid testing in the field [15,17,25–31].

Case Study 1: Leveraging community-based HIV testing campaigns for noncommunicable diseases in Uganda

Chamie et al. [15] evaluated the feasibility and diagnostic yield of integrating community-based HIV and NCD screening and referral in three well known community locations in a rural district. Local village governments were engaged prior to the campaign to plan for community mobilization, disseminate information, and maximize participation. Local healthcare workers trained and experienced in HIV counseling and testing conducted multidisease screenings for HIV, hypertension (HTN), and diabetes mellitus (DM) and held questionnaire-based interviews with community members. Patients screened positive for any disease were referred to nearby public health facilities. Most testing was done in the field using POC equipment while a central lab provided support for tuberculosis (TB) testing.

NCD screening required the addition of a point-of-care (POC) screening device for random blood glucose measurement and blood pressure machines with varying sized cuffs. The associated incremental cost of this was $2.41 per participant, onto a base cost of $26.69.

Among adults living in the catchment area, 74% participated with more of the female population (95%) reached compared with males (52%). Researchers found that 46% ofpatients who screened positive for HIV were newly diagnosed, while 65 and 23% of patients screened positive for HTN and DM, respectively, were newly diagnosed.

A key challenge was referral to different centers for care of HIV and NCDs because NCD care was only available at a center ~20 km away. Overall, a quarter of the target population did not take part in the screening campaign. Despite a high-throughput design, participants spent a median of 95 min at the campaign, longer for HIV- infected participants, which may have deterred participation. Linkage to care within 3 months was higher for NCDs but still suboptimal, at 39, 43, and 61% for HIV HTN, and DM patients respectively. A follow-up study among patients diagnosed with HTN included an intervention package (short counseling session after diagnosis, referral appointment within 30 days, and oneway transport cost facilitation) resulting in 83% linkage to care [29]. Tracing of patients not linking within 6 months revealed that the asymptomatic nature of HTN, as well as transport cost and inconvenience were significant barriers to linkage.

Screening for noncommunicable diseases and noncommunicable disease risk factors among people living with HIV at health facilities

Leveraging established HIV clinic infrastructure, this model targets PLHIV engaged in care and screens them for NCDs and NCD risk factors, tackling the problem of dual HIV/NCD burden [16–18,32–40].

Case study 2: Screening for noncommunicable diseases and their risk factors in people living with HIV enrolled in care in Tanzania

Kagaruki et al. [16] evaluated the magnitude and risk factors of DM and HTN among PLHIV in two Tanzania regions (one rural and one urban). They screened PLHIV in 12 HIV care and treatment centrers (CTCs) for DM, HTN, and NCD risk factors such as high low-density lipoprotein (LDL), low high-density lipoprotein (HDL), suboptimal intake of fruits and vegetables, lack of participation in vigorous activity, body mass index 25 kg/m² at least and abnormal waist circumference. Screening utilized a structured tool adopted from the WHO STEPs survey available in both English and the local language [41]. Qualified medical personnel were responsible for data collection, anthropometric measurements, and blood sample collection, following a 3-day training.

Of the 671 PLHIV participants, HTN and DM was prevalent in 26.0 and 4.2%, respectively. Prevalence of NCD risk factors were low HDL (72%), suboptimal fruit and vegetable consumption (70%), poor participation in vigorous activity (48%), abnormal waist circumference (47%), and high LDL (43%). All patients received health education based on their screening findings and a paper copy of their results. For patients with NCDs or NCD risk factors, study personnel communicated their information to the patient’s specific CTC for further workup and management.

Key challenges were failure to return for drawing of fasting blood samples despite assurance of compensation for transport, and low participation by male PLHIV (30%) and ART-naive PLHIV (47%) in the NCD screening who cited lack of time to participate. Linkage-to-care rates and follow-up clinical outcomes for PLHIV with NCDs or NCD risk factors were unavailable as this was a research study.

Integrated approaches to care of HIV/ noncommunicable disease patients

External funding for NCD care in LMICs remains low, estimated at 1.3% of total development assistance for health in 2015 [42]. Given the large investment in HIV care in SSA, leveraging HIV infrastructure represents a key opportunity to provide NCD care to large populations without needing to replicate health service streams. We identified several examples of integrated HIV and NCD screening, treatment, and follow-up, which we divided into two distinct models: integrated HIV and NCD care within chronic disease care [17] and HIV care [18] clinics, and differentiated care for stable HIV and/or NCD patients in medication adherence clubs [19].

Case Study 3: Leveraging HIV platforms to work toward comprehensive primary care in Malawi

Wroe et al. described the implementation of decentralized integrated chronic care clinics (IC³) in rural Malawi where patients with HIV and/or NCDs receive care for chronic disease [17]. The IC³ model follows the original patient flow designed for HIV care beginning with screening (both community-based and facility-based) and referral for follow-up of any and all chronic conditions. Patients receive education on common conditions before seeing clinicians trained in managing HIV and/or NCDs. Finally, patients collect their medicines and are assigned a new appointment date. Defaulter tracing occurs for patients lost to follow-up using protocols originally designed for PLHIV.

In the district where the effort was described, 7100 PLHIV received decentralized HIV care across two hospitals and 11 health centers. Prior to IC³, only two centers provided NCD care with limited success, including a high loss to follow-up rate related to patients either having to travel long distances for NCD care or requiring different clinic visits for patients with comorbid HIV/NCD. In response, IC³ was launched and decentralized to all 13 facilities in the district. To overcome human resource constraints, existing HIV-trained personnel were converted into integrated chronic disease management providers through classroom training and continuous on-the-job mentorship and supervision on NCD screening and treatment. Patient data management was re-designed for more comprehensive and integrated data collection via creation of master files for each patient that held all information instead of having multiple files on the different disease states.

A clear patient flow system was a key element in ensuring enhanced efficiency in the IC³ without imposing significant increases in workload for the care providers. An assessment of each health worker’s role in the IC³ identified a straining workload on the nurses, which was solved through task re-distribution to improve efficiency (Dr Emily Wroe, personal communication, 2017) [17].

As of May 2015, 6781 patients on ART and 721 patients with NCDs (HTN, DM, epilepsy, or asthma) were receiving care in IC³. Among the NCD patients, 109 (15%) were PLHIV Medications were provided free of charge which necessitated additional funding for NCD drugs to be provided by the implementing partner. Although clinical outcomes are yet to be described, a detailed toolkit for implementers of integrated HIV/ NCD care is available online [43,44].

Additional experience in integrated HIV/NCD care comes from Patel et al. [18] who described an effort to integrate HTN management at the Lighthouse Trust HIV service delivery sites in Malawi using a health system strengthening approach [45] utilizing evidence-based tools and practices, and continuous training of healthcare workers to improve clinical outcomes. An HTN-specific electronic medical record module was designed for monitoring and evaluation ofboth clinical and programmatic outcomes. A phased approach was used to implement HTN screening to ensure that clinic wait times and staff workload were not increased. At 12 months, of 29 359 individuals screened, 11% were newly diagnosed with HTN, and 85% of those with hypertension received treatment per standardized protocols. Among persons with mild and moderate HTN, blood pressure (BP) control rates were 38 and 30% after 6 months of treatment, respectively. Notably, adherence to ART was not affected by the additional burden of antihypertensive medications. Cost-effectiveness analyses are underway. The main challenge to scale-up of this program was noted as variability in accessibility and availability of antihypertensive medications because Malawi experiences frequent stockouts.

Integration of differentiated care for HIV/ noncommunicable disease

Differentiated care is care delivery that is customized to the individual patient’s needs [46] allowing for longer periods between clinic follow-up among stable HIV patients, leading to a reduced burden on both the patient and care provider. The benefits of differentiated care for PLHIV can be extended to HIV/NCD integrated care as demonstrated by the following case study.

Case study 4: Differentiated care for HIV/ noncommunicable diseases in Kenya

Khabala et al. [19] described an integrated model encompassing principles of differentiated care for patients with HIV, HTN or DM in a low-income population in Kenya. Groups of 25–35 stable patients with HIV HTN and/or DM were established. To be eligible to join, HTN and DM patients had to be at least 25 years of age, been on medications more than 6 months, and have a BP less than 150/100 and/or HbA1C less than 8%. PLHIV had to be at least 25 years of age, on ART for more than 1 year, have an undetectable viral load, a CD4 count more than 200, and not be in active WHO Stage 3/4 disease. Patients were informed that groups would have a mix of HIV and NCD patients but disclosure of their disease state was voluntary. The groups met quarterly in a dedicated space at the health center for a nurse-led session of approximately 2 h where they were assessed for clinical stability and received health education and drug refills. Usual clinic follow-up would occur annually, if a patient developed complications, or if they no longer met above stability criteria.

Over 1 year, 1432 patients across 47 MACs had 109 meetings and 2208 consultations (nurse-led weight and BP assessment, and ordering of routine blood tests). There was high adherence (99%) to recommended BP checks, weight checks, and blood tests by the nurse, with an overall low loss to follow-up (3.5%) or need for referral back to a clinic (2%) among members. Clinical outcomes are yet to be described.

Integrated comprehensive care for all

Early experiences with providing HIV care identified significant socioeconomic determinants of health in PLHIV in low-income settings such as food insecurity and undernutrition, and cost and logistical barriers to chronic care [47,48]. Similar determinants affect outcomes in NCDs and may be more important as few programs fully fund NCD care, often requiring user-fees for diagnostic tests, consultations, and drug purchases [20]. A population health model that builds on the HIV care infrastructure and lessons learned potentially represents the apex of integrated care [49].

Case Study 5: Delivering population health in Western Kenya

In Western Kenya, care of PLHIV has provided important experiences in delivering chronic care to SSA populations [41,50]. Several principles learned from these experiences have been leveraged and adapted to deliver NCD care [21]: home-based and community-based screening to improve NCD case-finding [51], task-shifting and decentralizing chronic care delivery to improve linkage and retention [50,52,53], using portable electronic medical records to streamline documentation [54,55], backing-up the Ministry of Health (MOH) medicines supply chain to ensure consistent availability [56], integrating income-generation and microfinance activities into care delivery to address socioeconomic barriers to health [20,52], and provision of affordable health insurance to minimize out-of-pocket costs [22].

A population health model grounded on the above principles has been developed to provide decentralized comprehensive care, including HIV/NCD, to the smallest administrative unit of the population (village) via community groups. These groups double both as convenient healthcare delivery points where clinical staff provide a variety of services, and as microfinance groups that provide low-interest loans and financial advice to members [22]. Collaboration with the Kenyan National Hospital Insurance Fund (NHIF) ensures that healthcare costs remain affordable to the majority of the population as enrollees are only required to make a monthly contribution of ~$5/month. Revolving fund pharmacies (RFPs) which utilize money collected from drug sales to cover drug re-stocking, have been established to protect against drug stock outs in government facilities [56], and a referral network has been built for patients who need to see higher cadres of staff. Clinical and process outcomes for the population health model are yet to be described.

Discussion

Designing a responsive continuity of care model for HIV provides vital lessons that can be leveraged to address the growing NCD burden that threatens aging PLHIV and the general SSA population [7,57,58]. HIV/NCD care integration is a feasible approach to health system strengthening in SSA, and the case studies described above demonstrate a variety of HIV/NCD integration models which programs can adopt and adapt based on available resources, needs and priorities. Several common themes from the reviewed models are worth highlighting, with lessons learned and prevailing research gaps summarized in Table 2 [15–22].

Table 2.

Lessons learned from integrated HIV/noncommunicable disease screening and care programs and prevailing research gaps.

Integrated HIV/NCD model	Lessons learned	Research gaps
Integrated HIV/NCD	Multidisease screening campaigns address shared	What is the cost-effectiveness of community based
Screening	barriers to chronic disease diagnosis and normalize	integrated screening?
	HIV screening	What is the cost-effectiveness of facility based NCD
	Training existing healthcare personnel to perform	screening in PLHIV?
	screening activities is a feasible approach to expand	How can case finding be optimized in integrated HIV/
	HIV/NCD screening	NCD screening programs?
	Equipping primary healthcare facilities with HIV/NCD	What are the clinical outcomes of early HIV/NCD
	care capacity may improve linkage following	diagnosis following screening?
	screening programs	What are the linkage and retention in care rates among
	Programmatic changes requiring regular screening for	PLHIV diagnosed with NCD or NCD risk factors?
	NCD and their risk factors among PLHIV required	How can integrated HIV/NCD screening models be
	Targeted health promotion required for PLHIV engaged	effectively scaled up?
	in care regarding NCD and their risk factors	How can integrated HIV/NCD screening models be  made sustainable?
Integrated chronic	Transforming HIV care personnel into integrated chronic	What is the cost-effectiveness of various models of
disease care	care providers feasible solution for human resource	integrated HIV/NCD care?
	shortage	What are the clinical outcomes for integrated HIV/NCD
	Clear patient flow coupled with clear provider roles	care?
	critical to minimizing clinic workload and	What is the effect of integration on stigma for HIV or
	streamlining patient care	NCD patients receiving care in integrated settings?
	Care protocols support task redistribution by	What is the effect of NCD integration on retention in care
	standardizing care procedures	for PLHIV?
	Adopting and adapting defaulter tracing strategies from	How can integrated HIV/NCD screening models be
	HIV care to NCD follow up can improve retention	effectively scaled up?
	Including programs to address socioeconomic barriers to	How can integrated chronic disease care models be
	access can incentivize retention in care	made sustainable?

DM, diabetes mellitus;HTN, hypertension; NCD, noncommunicable disease;PLHIV, people living with HIV.

Leveraging existing human resources is a key strategy to address shortfalls in human resources for health (HRH) [59] and was a common theme across our reviewed models. Use of existing medical personnel to conduct HIV/NCD screening and referral minimized training needs [15,16], task redistribution streamlined integrated HIV/NCD care delivery [17,19], and continued training and mentorship enabled transformation of HIV care providers into integrated chronic care providers to address staff shortages [17]. As SSA countries grapple with addressing the emerging NCD threat, a key intervention to consider is the creation of curricula to produce integrated chronic care providers instead of specific staff dedicated only to HIV or NCD roles [59].

Integrated HIV/NCD screening and NCD screening among PLHIV while feasible, required linkage and retention in care to reap the full benefits of early diagnosis. Linkage to care was poor following the community based integrated screening campaign described above but was noted to be higher in patients with NCDs compared to HIV [15]. Whilst sensitization on the need for care among diagnosed patients following screening may improve linkage [29], decentralized, integrated HIV/NCD care, particularly in remote areas, enhances the benefits of screening programs through linkage and retention [15]. In Kenya, integrated HIV/NCD care resulted in high retention rates [19] and was implemented to curb a high loss to follow-up associated with seeking care in distant facilities in Malawi [17]. Decentralization aims to bring care closer to patients to minimize logistical barriers to access, while reducing congestion at ‘central’ health facilities [20].

Streamlining service delivery is an important strategy in optimizing patient-centered care [60] and was key to delivering decentralized integrated care. This was made possible by clarifying individual health worker roles to promote staff buy-in, identify systemic challenges, and reduce strife among workers [17]. In addition, use of integrated files and health information technology tools minimized data management redundancies and improved efficiency, while providing a platform for monitoring patient and program progress [44,55]. Integrated MAC groups decentralized care by leveraging differentiated HIV care aspects [47,61] to provide flexible follow-up and medication refills to stable HIV and/or NCD patients, leading to improved patient satisfaction and decreasing the burden on the health system [19].

Public-private partnerships (PPP) between government agencies, health ministries, nongovernmental agencies (NGOs), federal programs, and academic partners were crucial to the success of integrated HIV/NCD models. Engagement with local government ensured community health needs were met to improve participation in a multidisease screening campaign in Uganda [15] while NGOs augmented government efforts through supplemental funding for personnel and NCD medication in Malawi and Kenya to ensure uninterrupted care [17,56]. Indeed, reviewed case studies all relied on a HIV platform established through PPP, to deliver integrated screening and/or care. Beyond ensuring interventions meet specific population health needs and facilitating implementation within existing regulatory frameworks, PPP are crucial in promoting sustainability of donor funded programs beyond funding cycles by incorporating successful programs into health policy [62].

Designing patient-centered quality care results in a higher likelihood of patient uptake and was a common theme in the reviewed models. Holding screening campaigns in three popular community locations improved participation in Uganda [15] while decentralized care and efficient clinic patient flow systems aimed to address logistical barriers for patients seeking HIV/NCD care in Malawi [17]. Integrated MAC group meetings in Kenya utilized flexible timing to improve patient convenience [19], and microfinance groups were established to address economic barriers to access and incentivize retention in care [20,52]. Delivering quality chronic care to low-income populations with limited capacity to pay remains a significant global health challenge [63]. Several programs have overcome this by providing HIV and/or NCD care free of charge to patients [18]. However, long-term sustainability of this model of service delivery remains a concern. Imposing user-fees for care services and medicines may promote sustainability but represents a significant barrier to sustained access in low-income populations [64,65]. Microfinance groups, income-generation programs and low-cost health insurance are several programs underway in Western Kenya to minimize the economic impact of receiving NCD care, for which, unlike HIV care, patients often pay out-ofpocket [49,50,52]. Ultimately, countrywide adoption of universal healthcare coverage, which has been on the SSA agenda since the late 1970s [49,66,67], is needed.

Our review has several limitations. First, it was not systematic as we aimed to describe existing models of HIV/NCD care integration, adopting a wide search strategy that was not amenable to the narrow research question requirements of a systematic review. Second, although we attempted to make contact with author leads of the case studies, we were unable to conduct interviews with all of them, possibly missing out on recent updates regarding available models. Third, case study descriptions only highlight key components in relation to HIV/NCD integration as described in the retrieved literature and author interviews and may miss out on other key programmatic aspects. Therefore, the summary here is a reflection of current efforts and may not capture ongoing HIV and/or NCD care activities that have not been published. In addition, overlap exists across the care cascade and extends to the described case studies, description of program activities under a specific model is meant only to highlight key components of the integration model, and not to imply that these are the only components of integration within the program. Finally, our review was primarily confined to discussing different typologies of HIV/NCD integration, rather than how such models are taken to scale [68]. Further research is warranted to determine how and where these models can be implemented successfully.

Nevertheless, our review illustrates that HIV/NCD care integration in SSA is feasible, with several models available that country programs can adopt and adapt based on available resources, needs, and priorities. Integration models are in their infancy, as exemplified by the general lack of clinical and process outcomes data, and a lack of cost-effectiveness data from the various models. These are urgently required to further inform implementers and policy makers as SSA continues to strengthen its health system in order to cope with the emerging health and economic threat posed by NCDs [58,69,70].

Conclusion

Leveraging the existing HIV infrastructure to provide NCD care to the SSA population is feasible. Several models of care integration have been described in SSA with important lessons that will aid context-specific replication in other SSA settings. Future efforts will need to factor in descriptions of process metrics and cost- effectiveness to further guide implementation, as well as clinical outcomes to aid decision makers.