The terms “public health,” “international health,” and “tropical medicine” are often used interchangeably with “global health,” so it is no wonder that there has been confusion as to what “global health” actually means. Recently, professionals in the field of global health have acknowledged the importance of defining this term succinctly, though this has proven difficult due to the field’s comprehensive and interdisciplinary nature.(1)
Members of the Executive Board of the Consortium of Universities for Global Health define “global health” as “an area for study, research, and practice that places a priority on improving health and achieving health equity for all people worldwide.”(2) Regardless of any definition, the practice of global health is best understood by its goals, actions, and outcomes, as well as how they affect the health and quality of life of the global community.(3)
Article 25 of the 1948 Universal Declaration of Human Rights declares that, “everyone has the right to a standard of living adequate for the health of himself and of his family.”(4) Unfortunately, the health disparity between high-income and low-income countries, as well as between individuals within a country, often makes this impossible, leaving many people living in unhealthy settings without sufficient access to care.
The field of global health is concerned with the health of populations worldwide, focusing on issues that typically have global, political, and economic significance. These health issues usually transcend national boundaries or are affected by transnational determinates, and are best solved through international collaboration.(5) Global health initiatives aim to improve the health and wellbeing of impoverished, vulnerable, and underserved people worldwide.(6) These initiatives include poverty reduction strategies, disease prevention measures (for HIV/AIDS, malaria, and tuberculosis, for instance), efforts to improve nutrition and food security, policy to raise environmental standards and living conditions, and the promotion of gender equality.
Just as global health measures cover a variety of topics, research in this area is similarly multidisciplinary, encompassing approaches from both the medical and social sciences, including epidemiology, economics, anthropology, demography, and sociology. Global health researchers attempt to identify epidemics or regions with a high prevalence of disease, and subsequently analyze the underlying causes of disease and poverty. The ultimate goal is to improve health worldwide and reduce existing disparities. The scope of global health research includes local, national, and international issues, and focuses on the planet as a whole, rather than as a collection of disparate countries.(7) Research provides evidence-based information necessary to develop plans for disease prevention and treatment, health promotion, and poverty reduction. The knowledge acquired through research can help prevent or control disease through interventions that involve new and innovative technologies, health policies, health services, or behavior change. The social science aspect of global health research is critical to providing context-specific information about health topics. This field is rapidly expanding as professionals in more disciplines are becoming interested in using their skills to improve the health of underprivileged populations and to reduce poverty.(8)
There is a pronounced difference between the disease burdens that developing and developed countries face today. Since antibiotics, vaccines, and other critical medical technologies have become widely available in developed countries, the burden of infectious diseases has steadily lessened.(18) Today, the healthcare systems of high-income countries are overwhelmed by the impact of chronic, non-communicable diseases such as heart disease, cancer, and diabetes. Developing countries, on the other hand, are plagued by infectious diseases. Ischemic heart disease is the leading cause of death in middle- and high-income countries, and the fourth leading cause of death in low-income countries.(19) Lower respiratory infections, diarrhea infections, HIV/AIDS, malaria, and tuberculosis are the top causes of death by infection in low-income countries, though they are relatively nonexistent in affluent countries.(20) In Africa, HIV/AIDS continues to be the primary cause of adult mortality.(21) Table 2 shows the top ten leading causes of death for low-, middle-, and high-income countries.
Global Disease Burden
The distribution of deaths also differs between high-income and low-income countries. While in sub-Saharan Africa, about half of all deaths are among children who are under fifteen years old. However, in wealthier regions, children comprise less than 1% of all deaths.(22) In 2004, children under five years of age made up 20% of deaths worldwide, mostly due to pneumonia, diarrhea diseases, and low birth weight.(23) Seven out of ten childhood deaths worldwide occur in sub-Saharan Africa or Southeast Asia.(24) The high rates of infant and childhood deaths in these regions are attributable to poor environmental conditions, inadequate nutrition, or lack of medical attention.
The Double Burden of Disease
There has been a rapid increase in the prevalence of non-communicable diseases in developing nations, though infectious diseases continue to be the leading cause of mortality.(25) Worldwide, the prevalence of cardiovascular disease, cancer, and diabetes has been on the rise. Developing countries are now facing a double burden of disease in which they must deal with both communicable and non-communicable diseases. This is a daunting task, as the public health sectors of most developing countries are already overwhelmed. In fact, some studies have reported that 79% of all deaths caused by chronic disease occur in developing countries.(26) High-income countries have the infrastructure and resources to prevent and treat these types of diseases. The health systems of developing countries, however, typically suffer from poor infrastructure, and lack the newer technologies available to wealthier nations; therefore, they are harder hit by disease epidemics.(27)
Sub-Saharan Africa has a particularly high burden of communicable and non-communicable diseases compared to the rest of the world. In 2004, while infectious diseases caused more than half of all deaths, over 25% of deaths were due to non-communicable diseases; ever since, their prevalence has been increasing.(28) While health interventions in sub-Saharan Africa and other developing regions focus primarily on infectious disease, it is important to recognize the tremendous impact that non-communicable diseases have on these populations. Though researchers are dedicated to combating illnesses such as cancer, diabetes, and heart disease in the developed world, these studies are far more limited in the context of developing nations. More work must be done to examine the prevalence and risk factors associated with these diseases in the developing world.
Table 2: Top 10 Leading Causes of Death in Low-, Middle-, and High-Income Countries
Reproduced from the World Health Organization website (29)
|Low-income countries||Middle-income countries||High-income countries|
|1||Lower respiratory infections||Ischemic heart disease||Ischemic heart disease|
|2||Diarrheal diseases||Stroke and other cerebrovascular diseases||Stroke and other cerebrovascular diseases|
|3||HIV/AIDS||Chronic obstructive pulmonary disease||Trachea, bronchus, lung cancers|
|4||Ischemic heart disease||Lower respiratory infections||Alzheimer and other dementias|
|5||Malaria||Diarrheal diseases||Lower respiratory infections|
|6||Stroke and other cerebrovascular diseases||HIV/AIDS||Chronic obstructive pulmonary disease|
|7||Tuberculosis||Road traffic accidents||Colon and rectum cancers|
|8||Prematurity and low birth weight||Tuberculosis||Diabetes mellitus|
|9||Birth asphyxia and birth trauma||Diabetes mellitus||Hypertensive heart disease|
|10||Neonatal infections||Hypertensive heart disease||Breast cancer|
Quantifying National Health and Development
In order to identify the health needs of a population and to track developmental progress, researchers use measurements to quantify the disease burden, health standards, educational standards, and economic factors of a country. Many of these measurements are known as “indicators,” since they indicate disease burden or health status.(30) The following is a list of key indicators:
- Adult Mortality Rate: The probability of a person dying between the ages of 15 and 60 per 1,000 people in a population.
- Child Under Five Mortality Rate: The number of children who die before reaching the age of five, per 1,000 live births, per year.
- Infant Mortality Rate: The number of infant deaths before reaching one year of age, per 1,000 live births, per year.
- Maternal Mortality Rate: The average number of female deaths caused by pregnancy, during childbirth, or within 42 days of being pregnant, per 100,000 live births, per year.
- Neonatal Mortality Rate: The number of deaths during the first 28 days of life per 1,000 live births, per year.
- Birth Rate: The number of childbirths per 1,000 people per year in a population.
- Rate of Natural Increase: The crude birth rate minus the crude death rate (i.e. mortality rate) of a population.
- Population Growth Rate: The rate at which the number of individuals in a population increases over time.
Health of the Population
- Children Under Five Underweight: The %age of underweight children aged 0-5 years in a population. (Being underweight is defined as being less than -2 standard deviations from the WHO Child Growth Standards median, which uses weight-for-age calculations.)
- Density of Physicians: The number of medical doctors available to the public per 10,000 people.
- Disability-Adjusted Life Years (DALYs): A measure of disease burden, expressed as the number of years of healthy life lost due to disability, illness, or early death. One DALY is equivalent to one year of healthy life lost.(31)
- Disease Prevalence (HIV/AIDS, malaria, tuberculosis, etc.): The estimated number of adult cases of disease, typically expressed as a %age of the population.
- Healthcare Expenditure: Total funds spent on health as a %age of a country’s gross domestic product (GDP).
- Life Expectancy at Birth: The average number of years a newborn is expected to live, given a specific year, country of birth, and gender.
- Low Birth Weight Newborns: The %age of live births that weigh less than 2,000 grams, out of the total number of live births per year.
- Morbidity Rate: The number of individuals in poor health due to disability or disease during a given time.
- Gini Coefficient: A measure of income disparity among a population, expressed as a value between zero and one, where zero expresses total equality and one expresses maximum inequality.
- Gross Domestic Product (GDP): The market value of all goods and services produced within a country over a specific time period. GDP per capita is an indicator of a country’s standard of living.
- Adult Literacy Rate: The %age of a population (over the age of fifteen) who can both read and write.
- Children Out-of-School: Number of primary aged children not attending school per 1,000 children.
- Education Expenditure: Total funds spent on education as a %age of a country’s GDP.
Each year, the World Bank publishes a collection of international development indicators that presents global development data for both developing and high-income countries, entitled “World Development Indicators.” This also includes progress made towards reaching the MDGs. To view each annual edition online, visit http://data.worldbank.org/data-catalog/world-development-indicators.
(1) Beaglehole, R. & Bonita, R. (2010). What is global health? Global Health Action, 3: 5142.
(2) Koplan, J.P., Bond, T.C., Merson, M.H., Reddy, K.S., Rodriguez, M.H., Sewankambo, N.K., et al. (2009). Towards a common definition of global health. The Lancet 373:1993-1995.
(5) Brown, T.M., Cuento, M., & Fee, E. (2006). The World Health Organization and the transition from ‘international’ to ‘global’ public health. American Journal of Public Health, 96(1):62-72.
(6) Koplan, J.P., Bond, T.C., Merson, M.H., Reddy, K.S., Rodriguez, M.H., Sewankambo, N.K., et al. (2009). Towards a common definition of global health. The Lancet 373:1993-1995.
(7) Beaglehole, R. & Bonita, R. (2010). What is global health? Global Health Action, 3: 5142.
(8) Macfarlane, S.B., Jacobs, M., & Kaaya, E.E. (2008). In the name of global health: trends in academic institutions. Journal of Public Health Policy, 29:383-401.
(9) Balcius, J., & Novotny, T.E. (2011). New approaches to global health governance: the evolution to public-private partnerships. Journal of Commercial Biotechnology, 17:233-240.
(12) Brown, T.M., Cuento, M., & Fee, E. (2006). The World Health Organization and the transition from ‘international’ to ‘global’ public health. American Journal of Public Health, 96(1):62-72.
(13) Waage, J., Banerji, R., Campbell, O., Chirwa, E., Collender, G., Dieltiens, V., et al. (2010). The Millennium Development Goals: a cross-sectoral analysis and principles for goal setting after 2015, The Lancet, 376:911-1023.
(15) Waage, J., Banerji, R., Campbell, O., Chirwa, E., Collender, G., Dieltiens, V., et al. (2010). The Millennium Development Goals: a cross sectoral analysis and principles for goal setting after 2015, The Lancet, 376:911-1023.
(18) Brown, T.M., Cuento, M., & Fee, E. (2006). The World Health Organization and the transition from ‘international’ to ‘global’ public health. American Journal of Public Health, 96(1):62-72.
(19) The World Health Organization (2008). The top 10 causes of death fact sheet. Retrieved October 10, 2011, from <http://www.who.int/mediacentre/factsheets/fs310/en/index.html>.
(21) Global burden of disease The World Health Organization (2004). The global burden of disease 2004 update. Retrieved October 10, 2011, from <http://www.who.int/healthinfo/global_burden_disease/2004_report_update/en/index.html>.
(25) Boutayeb, A. (2006). The double burden of communicable and non-communicable diseases in developing countries. Royal Society of Tropical Medicine and Hygiene, 100:191-199.
(28) Dalal, S., Beunza, J.J., Volmink, J., Adebamowo, C., Bajunirwe, F., Njelekela, M., et al. (2011). Non-communicable diseases in sub-Saharan Africa: what we know now. International Journal of Epidemiology, 40:885-901.
(29) The World Health Organization (2008). The top 10 causes of death fact sheet. Retrieved October 10, 2011, from <http://www.who.int/mediacentre/factsheets/fs310/en/index.html>.
(31) The World Health Organization (2009) Global health risks: mortality and burden of disease attributable to selected major risks. Retrieved October 10, 2011, from <http://www.who.int/healthinfo/global_burden_disease/global_health_risks/en/index.html>.