Achieving a “Grand Convergence” in Global Health:

Modeling the Technical Inputs, Costs, and Impacts from 2016 to 2030 

Human health can be divided into two distinct historical phases. The first phase, which ended about 200 years ago, may be best described as Hobbesian: nasty, brutish and short. High rates of infant and young child mortality yielded mean life expectancies of less than 40 years, and relatively few people lived to old age. Globally, Homo sapiens was a high-mortality, high-fertility species, with relatively modest differences in health outcomes across geographies and communities. 1,2 Although mean life expectancies did improve over the course of this first phase, the pace of improvement was very slow. The second phase in human health started roughly at the beginning of the 18th century. Triggering factors included greater wealth from industrialization and trade, improvements in agricultural productivity, advances in science and education, improvements in infrastructure, and an initial wave of public health interventions, such as improved water and sanitation. These changes, along with subsequent advances in medical technologies, enabled wealthier countries to increase the life expectancy of their populations. Infant mortality declined sharply in the industrializing world. Additional health advances led to subsequent declines in mortality rates among older generations. These improvements, however, primarily benefited richer economies and communities. Poorer nations saw their health outcomes improve, but at a much slower rate than their wealthier peers, leading to a “great divergence” in global health. And in wealthier economies, significant disparities in health persisted between wealth quintiles and different demographic groups. We are still in this second phase of human health, one marked by a sharp divergence of health outcomes between rich and poor nations and communities. The World Bank estimates that average life expectancy in Sub-Saharan Africa in 2012 was just 56 years, and under-5 mortality was 97.6 per 1000 live births. 3 These figures contrast with life expectancy of 80 years and an under-5 mortality rate of just 5.5 deaths per 1000 live births in high income countries. While a range of efforts and commitments by international and domestic players have yielded significant progress in global health over the last 20 years, a substantial burden of avertable mortality and morbidity persists in low-income countries. Last year, the Lancet Commission on Investing in Health (CIH) addressed the question of whether the world could enter a third phase of human health—one in which poorer countries would see their infectious, maternal, and child health outcomes converge with the higher levels of wealthier nations—through increased investments in health interventions and systems to combat common causes of mortality and morbidity. 4 In recent years, a number of investment cases have been developed to address the costs of (i) fighting specific infectious diseases, such as HIV/AIDS, malaria, tuberculosis (TB), diarrhoea and pneumonia; 5–8 (ii) rolling out specific categories of health interventions, such as immunization or nutrition; 9,10 (iii) supporting continued innovation in health technologies for low-income nations; 11 (iv) targeting specific vulnerable populations, such as mothers and young children12–14, or certain geographic regions; 15 and (v) scaling up innovative financing for health systems to achieve the Millennium Development Goals (MDGs). 16 While these analyses have all addressed important individual questions, none focused specifically on whether a global convergence in health outcomes could be achieved by investing comprehensively across a very broad range of health conditions. Building upon these existing models, the CIH collaborated with many international agencies and institutions to take an integrated approach across multiple conditions to determine if such a grand convergence in health was possible and what it might cost. The commission’s report “Global Health 2035” found that in less than a generation a significant global convergence could be realized. 4 With effective scale up of proven health interventions, strengthening of health systems, and sustained investment in innovation, by 2035 infectious, maternal, and child deaths rates in low-income countries (LICs) and lower-middle income countries (LMICs) could fall to levels seen today in high-performing middle-income countries. Examples of such “high performers” include the “4-C” middle-income countries, Chile, China, Costa Rica, and Cuba (Figure 1). Moreover, the average incremental cost of this investment in health was estimated at $64B to $83B per year in 2016-2025 and 2026-2035 respectively. This investment would yield returns that compare favorably to other potential investments available to developing countries and development agencies.