POLICY AND PRACTICE
A future without health? Health dimension in global scenario studies
La santé a-t-elle un avenir ? La dimension sanitaire dans les études de scénarios mondiaux
¿Un futuro sin la salud? Dimensiones sanitarias en los estudios de escenarios mundiales
Pim Martens1; Maud Huynen
International Centre for Integrative Studies, Maastricht University, PO Box 616, 6200 MD Maastricht, Netherlands
ABSTRACT
This paper reviews the health dimension and sociocultural, economic, and ecological determinants of health in existing global scenario studies. Not even half of the 31 scenarios reviewed gave a good description of future health developments and the different scenario studies did not handle health in a consistent way. Most of the global driving forces of health are addressed adequately in the selected scenarios, however, and it therefore would have been possible to describe the future developments in health as an outcome of these multiple driving forces. To provide examples on how future health can be incorporated in existing scenarios, we linked the sociocultural, economic, and environmental developments described in three sets of scenarios (special report on emission scenarios (SRES), global environmental outlook-3 (GEO3), and world water scenarios (WWS)) to three potential, but imaginary, health futures ("age of emerging infectious diseases", "age of medical technology", and "age of sustained health"). This paper provides useful insights into how to deal with future health in scenarios and shows that a comprehensive picture of future health evolves when all important driving forces and pressures are taken into account.
Keywords: World health/trends; Forecasting; Communicable diseases, Emerging/epidemiology; Biomedical technology; Sustainability; Health status indicators; Epidemiologic factors (source: MeSH, NLM).
RÉSUMÉ
Le présent article examine dans les études de scénarios mondiaux existants la dimension sanitaire ainsi que les déterminants socioculturels, économiques et écologiques de la santé. Sur les 31 scénarios étudiés, moins de la moitié décrivaient de façon satisfaisante les futurs événements sanitaires et tous les scénarios n'abordaient pas la santé de manière systématique. Toutefois, dans le domaine de la santé les forces motrices étaient en général suffisamment traitées : il aurait donc été possible que les futurs événements sanitaires en soient décrits comme un résultat. Pour montrer comment intégrer une dimension sanitaire dans les scénarios existants, nous avons relié les événements socioculturels, économiques et environnementaux décrits dans trois groupes de scénarios (rapport spécial sur les scénarios d'émissions SRES, l'avenir de l'environnement mondial 3 GEO3, et scénarios mondiaux relatifs à l'eau WWS) à trois situations sanitaires possibles mais imaginaires (l'ère des maladies infectieuses émergentes, l'ère de la technologie médicale et l'ère de la santé durable). Le présent article permet de mieux comprendre la façon de traiter les futures situations sanitaires dans les scénarios et montre que le tableau complet des problèmes de santé évolue lorsque l'on tient compte de toutes les forces motrices et pressions importantes.
Mots clés: Santé mondiale/orientations; Prévision; Maladies transmissibles émergentes/épidémiologie; Technologie biomédicale; Durabilité; Indicateur état sanitaire; Facteurs épidémiologiques (source: MeSH, INSERM).
RESUMEN
En este estudio se analizan las dimensiones sanitarias y los determinantes socioculturales, económicos y ecológicos de la salud en los estudios de escenarios mundiales ya existentes. Ni siquiera la mitad de los 31 escenarios analizados proporcionaba una buena descripción de la evolución futura de la salud, y los diferentes estudios de escenarios no trataron la salud de forma homogénea. No obstante, en los escenarios seleccionados se abordaban de forma adecuada la mayoría de las fuerzas impulsoras mundiales de la salud, por lo que hubiera sido posible describir la evolución futura de la salud como un resultado de esas múltiples fuerzas impulsoras. Para aportar ejemplos de cómo se puede incorporar el futuro de la salud a los escenarios existentes, relacionamos las evoluciones sociocultural, económica y ambiental descritas en tres grupos de escenarios (el Informe especial sobre los escenarios de las emisiones SRES , Perspectivas del medio ambiente mundial 3 GEO3 y Escenarios mundiales del agua WWS ) con tres posibles futuros sanitarios imaginarios («la era de las enfermedades infecciosas emergentes», «la era de la tecnología médica» y «la era de la salud sostenida»). El presente artículo permite comprender mejor cómo tratar la situación sanitaria futura en los estudios de escenarios y muestra que se puede obtener una visión global del futuro de la salud cuando se toman en consideración todas las fuerzas impulsoras y presiones importantes.
Palabras clave: Salud mundial/tendencias; Predicción; Enfermedades transmisibles emergentes/epidemiología; Tecnología biomédica; Sostenibilidad; Indicadores de salud; Factores epidemiológicos (fuente: DeCS, BIREME).
Health dimension in global scenarios
The value of scenarios to explore possible futures and provide sound, policy-relevant guidance for decision-makers is increasingly and widely recognized (Box 1). Scenarios have been generated about, for example, global climate change (1) and water utilization, availability, distribution, and quality (2), and an assessment of future ecosystem composition, structure, and function is in progress (3).
In today's era of globalization, global environmental change and the subsequent increasing concern for our present and future health, the call for good global health governance is growing stronger. Scenarios are useful tools for exploring possible global health futures, gaining insights with regard to (the driving forces of) global health, and supporting the decision-making process. To date, however, a set of global integrated scenarios on future health development has not been generated. Even worse, as described below, in most of the global scenarios developed, the health dimension is lacking completely.
With the following three criteria "integration", "long-range outlook", and "global scope" in mind, we considered eight scenario studies (with a total of 31 scenarios) published since 1995 (Table 1). With regard to the health dimension in the selected scenarios, only 14 of the 31 scenarios gave a reasonable description of future developments in health (Fig. 1). Nine scenarios described only specific pressures or drivers with regard to human health or only certain aspects of health (for example, mortality and water-related diseases). Eight scenarios completely neglected the health dimension. Only four scenarios explicitly discussed several sociocultural, economic, and ecological developments as determinants of health. The main global drivers and pressures of health were described adequately in most of the selected scenarios, with the exception of "education": only 14 scenarios described developments in "education", one mentioned that literacy goals were set, and 16 did not mention "education" at all (Fig. 1).
A mere 15% of the selected scenarios, therefore, describe health adequately and in an integrated way. Remarkable was the fact that of the six storylines developed by the Global Scenario Group, two described health specifically as an outcome of socioeconomic and environmental changes, one gave a reasonable description of future health, but health was absent in three of the scenarios. This indicates that health is not handled consistently within the current sets of scenarios. When we looked at the major global determinants of health, however, these were addressed adequately in most scenarios. It would have been possible, therefore, to describe the future developments in health as an outcome of these multiple drivers and pressures.
Future health ages
What health future lies ahead? We linked the three most recently developed sets of scenarios (special report on emission scenarios (SRES), global environmental outlook-3 (GEO3), and world water scenarios (WWS)) to potential future health ages (Box 2):
- Age of emerging infectious diseases: in which the emergence of new infectious diseases or the re-emergence of "old" diseases will have a significant impact on health, influenced by travel and trade, microbiological resistance, human behaviour, breakdowns in health systems, and increased pressure on the environment (11, 12).
- Age of medical technology: in which increased health risks caused by changes in lifestyle and the environment will be offset by increased economic growth and improvements in technology (13, 14).
- Age of sustained health: in which investments in social services will lead to a sharp reduction in lifestyle-related diseases, most environmentally related infectious diseases will be eradicated, and disparities in health between rich and poor countries eventually will disappear (15).
Although these stages are imaginary (even though some features already are recognizable in some countries) and are not delineated sharply, they could follow from ages in the health transition, as we have seen in the past and are facing now (16) (Box 2). The projected picture of future health in a particular scenario evolved from our interpretation of the combination of the described future developments in the determinants of health.
The health futures of the SRES, GEO-3 and WWS scenarios are diverse, and we must keep in mind that the timeframes of these scenarios differ (10). Beneath the diversity of the studies in terms of the choice of scenario names and the narrative motivation for each storyline including our enrichment related to human health lies a common set of archetypal visions of the future:
- the world evolves gradually, driven by dominant driving forces;
- a strong policy push redirects development toward various environmental and social goals;
- global development succumbs to fragmentation, environmental collapse, and institutional failure; and
- a new form of development emerges from the challenges of globalization.
Looking at the health dimension we see that, on the one hand, in a future where a strong economic orientation prevails (WWS-BAU (Business-As-Usual) and WWS-TEC (Technology, Economics, and the Private Sector), and GEO3-MF (Markets First)), health developments in developing countries move towards the age of emerging infectious diseases, while the developed world manages to advance to the age of medical technology. On the other hand, the scenarios that emphasize international cooperation with a strong focus on meeting social and environmental sustainability goals (SRES-B1, WWS-VAL (Values and Lifestyles), and GEO3-SuF (Sustainability First)), are characterized by the advancement of developing and developed countries to the age of sustained health.
In between these "extremes", we see a spectrum of developments. For example, in the GEO3's Policy First (PF) scenario, advances towards sustainability are slow. The developing countries are not likely to advance beyond the age of chronic diseases, and the developed countries are not able to complete the transition to sustained health. Something similar is the case in the future of the SRES-B2 scenario, but in this differentiated world, some developing countries might achieve some modest technological progress that sends them on the way towards the age of medical technology. SRES-A1 describes a future in which developing countries may experience improvements in health and increased life expectancy, but at the same time do not "trade" infectious diseases for chronic diseases the so-called "double burden" of disease while the developed world reaches the age of medical technology. In the futures of the SRES-A2 scenario and the more "pessimistic" GEO3-SF (Security First), the developed world also is likely to experience this double burden of disease, while the developing countries shift into the age of emerging infectious diseases.
The way forward
The previous exercise shows that a comprehensive picture of future health can evolve from current global scenarios studies, and several reasons exist for integrating health in upcoming global scenario exercises (in, for example, the new scenarios that are being developed as part of the Millennium Ecosystem Assessment (3, 17)). Firstly, health can be seen as an important high-level integrating index that reflects the state and, in the long term, sustainability of our natural and socioeconomic environment. Population health, therefore, is central to the formulation of humankind's "sustainable development" trajectory (18). Secondly, global scenarios can provide narratively rich (although, in general, quantitatively coarse) descriptors across a range of possible global futures. These scenarios thus can provide good coverage of the initial array of "drivers and pressures" needed to assess health changes.
As good health is regarded by many as one of the most important assets of human life, why has so little effort been made to explicitly address human health in the past decade of scenario development? From the point of view of the global scenario community, projection of the potential health impacts of global changes poses a difficult challenge, in part because the sensitivity and adaptive capacity of exposed populations varies considerably depending on various factors, such as population density, level of economic and technological development, local environmental conditions, pre-existing health status, and the quality and availability of health care and public health infrastructure.
From a public health point of view, exploration of these global, long-term, and complex risks to human health seems far removed from the tidy examples that abound in textbooks of epidemiology and public health research. Health is only beginning to play a role in global scenario assessments, because of the above-mentioned complexities that beset research into human health impacts, compounded by an apparent diffidence on the part of most epidemiologists and other population health scientists to engage in this unfamiliar domain.
However, in order to connect current scenarios to a more robust analysis of changes in health will need further analysis. Ideally, new scenarios in which health is a key issue from the start of the process should be sketched; this would result in comprehensive and integrated descriptions of future health that are based on possible developments in the sociocultural, economic, and ecological drivers and pressures described in consistent storylines.
The integration of the health dimension into global scenario development has the potential to be instructive and exciting. International agreements and conventions regarding environment, energy, and many other issues need to be informed by the most comprehensive information about model estimates and scenario projections for the future and health should be an integral part of this information. 
Acknowledgements
We would like to thank all colleagues at the International Centre for Integrative Studies (ICIS) at Maastricht University for the fruitful discussions leading to this paper; special thanks to Dale Rothman and Ward Rennen. Also many thanks to Kris Ebi, Henk Hilderink, Johan Mackenbach and Colin Soskolne for comments on (parts of) earlier versions of the manuscript. This work is carried out within the Fulbright New Century Scholar Program "Challenges of Health in a Borderless World" and as part of a Friedrich Wilhelm Bessel Research Award, and is financially supported by the Dutch Institute of Public Health and the Environment (RIVM) within the project 'Globalisation, Environmental Change and Public Health'.
Conflicts of interest: none declared.
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1 Correspondence should be sent to Dr Martens at this address (email: p.martens@icis.unimaas.nl).