Published byAnnette Gerritsen
Published on29 November 2017
Rapid demographic, sociocultural, and economic transitions are driving increases in the risk and prevalence of diabetes and other non-communicable diseases (NCDs) in sub-Saharan Africa. The impacts of these transitions and their health and economic consequences are evident. Whereas, in 1990, the leading causes of death in sub-Saharan Africa were HIV/AIDS, lower respiratory infections, diarrhoeal diseases, malaria, and vaccine-preventable diseases in children, in more recent years, cardiovascular diseases and their risk factors are replacing infectious diseases as the leading causes of death in this region, and rates of increase of cardiovascular risk factors are predicted to be greater in sub-Saharan Africa than in other parts of the world. Thus, sub-Saharan Africa—which contains a high proportion of the world’s least developed countries—will face the multifaceted challenge of dealing with a high burden of infectious diseases and diseases of poverty, while also addressing the increasing burden of cardiovascular disease and its risk factors. At present, many of the health systems in sub-Saharan Africa struggle to cope with infectious diseases. Meeting the goals of the UN high-level meeting on NCDs (to reduce premature mortality from NCDs by 25% by 2025) and Sustainable Development Goals (SDGs; to reduce premature mortality from NCDs by a third by 2030) requires a coordinated approach within countries, which starts with a firm consideration of disease burden, needs, and priorities.
Diabetes is an exemplar risk factor of cardiovascular disease in that its prevalence tracks the transitions that lead to the precursors of cardiovascular disease—namely obesity and overweight. The prevalence of diabetes is increasing rapidly in sub-Saharan Africa.1 If left untreated, diabetes leads to a plethora of complications, both microvascular and macrovascular, that affect multiple physiological systems. Additionally, diabetes is closely associated with other cardiovascular risk factors, including hypertension and hypercholesterolaemia, which interact to exacerbate the risk of adverse outcomes. Thus, diabetes requires an interconnected, broad-based health system for its effective management. Improving the processes of care for people with diabetes should lead to improvement of health systems for many other conditions. If left unchecked, however, the adverse outcomes of diabetes and other cardiovascular risk factors could overwhelm health systems in sub-Saharan Africa and leave many of those affected with substantial morbidity and mortality. The interaction of diabetes with infectious diseases further increases the burden of illness on resource-constrained health systems. The Lancet Diabetes & Endocrinology Commission on Diabetes in sub-Saharan Africa was formed to ascertain the current burden of diabetes and its risk factors and outcomes in the region, to assess challenges faced by health systems in dealing with this burden, and to suggest potential solutions. We present the key messages of the Commission below and also suggest operational targets (panel 1) to help countries at all stages of development to transition to a state whereby the UN and SDG targets on NCDs can be achieved, if not surpassed.
Priorities and targets for diabetes care to 2030
When health resources are severely limited, difficult choices must often be made in the face of competing priorities. Our review of the challenges involved makes it clear that models of diabetes care for use in high-income countries are neither appropriate nor affordable in low-income or middle-income countries. We advocate the pursuit of a utilitarian approach to the provision of diabetes care in most sub-Saharan African settings, involving widely available inexpensive treatments for prevention of complications alongside strong public health measures to prevent increases in the prevalence of obesity and diabetes. Investment in preventing the consequences of diabetes will prevent the necessity of investing in wider-scale availability of expensive treatments to manage diabetes complications. Rigorous health-systems research and implementation science2 to accompany the introduction of new treatments or management strategies are key to ensuring that solutions are both fitting to a local environment and that results obtained can be of use to other countries. Funding for this type of research is urgently required.
We therefore propose a hierarchy-of-needs model of care on the basis of strategies known to work in other settings. This hierarchy is based on the Commissioners’ experience in both clinical care and health-system improvement and our review of the literature during the process of this Commission. The principles of this hierarchy are straightforward: each intervention should be evidence-based, effective, accessible, integrated, and affordable. Of key importance, the Commission calls for services for provision of care and diagnostics for diabetes, its risk factors, and its complications to be fully integrated to minimise the indirect costs to the patient of having to attend multiple clinic appointments.
The prerequisites for introduction of treatment modalities or therapies are education and structure. The aims of education are achieved at personal, community, and health-care-provider levels. At a personal level, the aim is to make the patient an active, informed partner in their own therapy rather than a passive recipient. At the community level, the aim is to increase understanding and awareness of diabetes and eliminate prejudice. Education of medical personnel is needed to raise awareness of the disease and the simplicity of its treatment, and also to counterbalance marketing and medical education campaigns by the pharmaceutical industry, which are typically slanted towards use of more expensive, patented forms of treatment. An appropriate structure for health-care delivery, which is embedded in the health system, is equally essential.
We have considered necessary care needs in terms of the level of service-provision development in countries. We progress from care that we consider to be essential (which we refer to as level one care) and recommend should be available in 100% of countries by 2020; to level two care, which we consider should be the next step when level one care is achieved and should be available in 75% of countries by 2020 and in 100% of countries by 2025; and then to level three care, which should be considered once other targets have been achieved. We recommend that level three care should be present in 50% of countries by 2020, 75% of countries by 2025, and 100% of countries by 2030 (table 1).
Key message 1: the true burden of diabetes, other cardiovascular risk factors, and macrovascular and microvascular complications in sub-Saharan Africa is unknown
Estimates from those countries in which high-quality data are available suggest that the increase in the prevalence of diabetes, other cardiovascular risk factors, and adverse outcomes is large and is expected to further increase. However, most countries do not have data or data collection systems that are sufficiently reliable to enable mounting of a commensurate health-system response. To plan such a response requires high-quality, population-representative data on both current burdens and associated demographic factors and that systems for longitudinal data collection be put in place. It is also imperative to ascertain which tests and cutoffs for hyperglycaemia are most appropriate for use in defining diabetes in populations in sub-Saharan Africa to prevent overtreatment or undertreatment.
Knowledge about the burden of type 1 diabetes is particularly important given that this condition is fatal in the absence of relatively inexpensive treatment.
Key message 2: diabetes and its consequences are costly to patients and economies
We estimate that, in 2015, the overall cost of diabetes in sub-Saharan Africa was US$19·45 billion or 1·2% of cumulative gross domestic product (GDP). Around $10·81 billion (55·6%) of this cost arose from direct costs, which included expenditure on diabetes treatment (eg, medication, hospital stays, and treatment of complications), with out-of-pocket expenditure likely to exceed 50% of the overall health expenditure in many countries. We estimate that the total cost will increase to between $35·33 billion (1·1% of GDP) and $59·32 billion (1·8% of GDP) by 2030. Putting in place systems to prevent, detect, and manage hyperglycaemia and its consequences is therefore warranted from a health economics perspective.
Key message 3: health systems in countries in sub-Saharan Africa are unable to cope with the current burden of diabetes and its complications
By use of information from WHO Service Availability Readiness Assessment surveys and World Bank Service Delivery Indicator surveys and the local knowledge of Commissioners, we found inadequacies at all levels of the health system required to provide adequate management for diabetes and its associated risk factors and sequelae. We found inadequate availability of simple equipment for diagnosis and monitoring, a lack of sufficiently knowledgable health-care providers, insufficient availability of treatments, a dearth of locally appropriate guidelines, and few disease registries. These inadequacies result in a substantial dropoff of patients along the diabetes care cascade, with many patients going undiagnosed and with those who are diagnosed not receiving the advice and drugs they need. We also noted scarce facilities to manage the microvascular and macrovascular complications of diabetes. Additionally, despite calls for adding the care of diabetes and other cardiovascular risk factors onto existing infectious disease programmes (such as those for HIV), we found little evidence that such combined programmes are successful at improving outcomes.
Key message 4: scarce health-care resources should be focused on the management of diabetes and other risk factors to prevent complications
The management of diabetes and its risk factors is reasonably simple and inexpensive. Treating complications, however, is costly, requiring providers with a high level of skill and specialised equipment. Prevention of complications is therefore crucial. To allow effective prevention of complications, de-centralisation of care—from experts who work in hospitals to community health workers and other non-clinical providers who work in the primary care system and deliver home-based screening and care—needs to be accelerated. Simple and effective information technology solutions should be used to enable more locally delivered care. An additional consideration is whether it is more beneficial to treat each risk factor associated with diabetes to predefined targets, or to consider risk factors collectively and aim to reduce overall risk. For both the prevention of macrovascular and microvascular risk factors, our analyses suggest it will be more effective and cost-effective to consider risk factors as a whole, and use benefit-based tailored treatment, rather than to treat each individual cardiovascular risk factor to a target.
Key message 5: more evidence is needed about the benefits and risks (to individuals and health systems) of screening before programmes are rolled out across sub-Saharan Africa
The benefits of screening, especially in people who are deemed to be at high risk, seem obvious: earlier detection and management of diabetes and its risk factors and prevention of costly complications. However, as of yet, there is little evidence—even from high-income countries, where studies have been done—that screening programmes are effective at reducing adverse outcomes. Additionally, the thresholds for diagnosing diabetes (ie, the level of glycaemia that is associated with the risk of adverse outcomes in the long term) and the best test to use are not defined for populations in sub-Saharan Africa. Hence, any screening programme that is started should only be done as part of a rigorous longitudinal outcomes study that also compares different tests for diagnosis of hyperglycaemia.