What is Global Health?

Global Health can be defined as “the goal of improving health for all people in all nations by promoting wellness and eliminating avoidable disease, disabilities, and deaths” (Institute of Medicine (US) Committee on the US Commitment to Global Health, 2009).

Others have expanded that definition, emphasizing priorities such as health equity (Koplan et al., 2009), transcending national boundaries (Kickbush, 2006), and collaboration between political, social, environmental and technological groups (Beaglehole & Bonita, 2010).

This course makes the following distinctions:

• Public health = health of a population in a specific community or country
• International health = emphasis on health issues in developing countries
• Global health = health for all people regardless of national boundaries.

In a review of 2022, the WHO listed the most significant global health issues confronting the planet in that year (World Health Organization, 2022c). This list provides a good overview of the many types of global issues that this course addresses.

• COVID-19: a partnership called ACT-Accelerator was developed to make pandemic tests and treatments available quickly (World Health Organization, n.d.-f)
• Mpox (formerly called monkeypox) was declared an international public health emergency (WHO Director-General, 2022)
• First new outbreak of Ebola in 10 years was reported in Uganda (World Health Organization, 2022b)
• Famine increased in the greater horn of Africa and the Sahel
• Devastation from the war in Ukraine produced healthcare emergencies and widespread mental health issues
• Childhood vaccination rates dropped markedly during the pandemic, especially for measles
• The world’s first malaria vaccine was rolled out
• A report was released of the top 19 fungi that pose the greatest threat to public health.

Why is it Important to Study Global Health?

Though some may wonder at the relevance of studying health issues that impact places and populations far from their homes, there are a number of arguments that can be made in favor of studying about and caring about global health. Observing the increases in life expectancy and reductions in mortality rates in recent decades allows us to appreciate the progress made in improving health. Such awareness shows we can improve health, inspires hope, and provides motivation for continued progress. Likewise, studying global health allows us to better understand what remains to be done and what should be addressed in the near future. A global perspective allows us to learn from the experience of other countries how health issues can be targeted quickly, effectively, efficiently, and fairly (Skolnik, 2023).

One argument in favor of studying global health is the increasing globalization of our world. We are more connected than ever before in history. As the world has just experienced recently with Covid-19, pathogens do not respect international or political borders. With the ease of air travel and increases in international commerce, it is possible for a pathogen to travel around the world in a matter of hours. Therefore, a health threat anywhere in the world is a health threat everywhere in the world. Covid-19 is a recent example of a newly emerging infectious disease; however, it is not the first, nor will it be the last new pathogen. In fact, the rate of emergence of new pathogens and the re-emergence of previously well-contained pathogens has been increasing in recent decades as a result of globalization and other factors (Lashley & Durham, 2007). It requires intense global cooperation to prevent and respond to outbreaks. The same is true for some other types of health concerns as well. For example, medications and vaccines, drug safety, and climate change are all issues that require shared financial resources and cooperation (Skolnik, 2023). No single country or government can manage these issues effectively on its own.

Covid-19 is also a great example of the connection between health and economics. The most recent pandemic not only resulted in a lot of death and suffering globally, it also disrupted global supply chains and negatively impacted economies. A study of global health makes the connection between health and economics clear. As you go through this course, you will have a better understanding of this bidirectional relationship – poverty is a social determinant of health; however, poor health also contributes to poverty. This relationship is true at both the individual and family level, as well as the national level. As you progress through this course, you will develop a deeper understanding of the social determinants of health by studying global health, which will help you to become a more effective health professional.

There is also an ethical argument for being concerned with global health rather than just with local health issues. One of the underlying values of global health, as defined in the preamble to the Constitution of the World Health Organization (World Health Organization, n.d.-a), is the belief that “the enjoyment of the highest attainable standard of health is one of the fundamental rights of every human being without distinction of race, religion, political belief, economic or social condition.” However, this value has been embraced by more than just the WHO and those working in global health. In fact, the Universal Declaration of Human Rights (UDHR) that was signed and adopted by all United Nations member countries in 1948 explicitly defines the right to a standard of living adequate for health and well-being as a universal human right (United Nations, n.d.). This implies access to tools necessary for health like essential health services, treatment for common infectious diseases, access to clean water and adequate nutrition for everyone in the world, regardless of where they live. Though the costs associated with ensuring these rights make them aspirational, especially in low-income countries, the UDHR implies that governments are expected to make progress towards providing their populations with the tools necessary for achieving the highest standard of health (Jacobsen, 2019). Nevertheless, there are many places in the world where this right to a standard of living adequate for health and well-being is not fully protected. While there is no consensus about exactly what obligations states have for ensuring the health of people beyond their geo-political borders, many argue that we do have a role to play. This may be especially true when it comes to health disparities.

Health differences, or health disparities, can be readily observed between countries around the world. For example, life expectancy at birth in high income countries is substantially higher than it is in low-income countries. According to data from The World Bank (n.d.), the average life expectancy at birth in high income countries in 2020 was 80 years compared to only 63 years in low-income countries. Such disparities between countries highlight areas of inequity, or unfairness. Health inequities can be defined as “differences in health that are not only unnecessary and avoidable, but also unfair and unjust” (Skolnik, 2023). The inequitable distribution of vaccines, medications, and other life-saving technologies are examples of problems that are part of the global health agenda. A desire to work to help overcome these health inequities is an important motivating force for many people who study global health.

The Sustainable Development Goals 

(United Nations Development Programme, n.d.-b)

The Sustainable Development Goals (SDGs) were adopted by the United Nations in 2015 as a universal call to action to end poverty, protect the planet, and ensure that by 2030 all people enjoy peace and prosperity.

The 17 SDGs are integrated, meaning that they recognize that action in one area will affect outcomes in other areas, and that development must balance social, economic, and environmental sustainability.

Countries have committed to prioritize progress for populations who are furthest behind. The SDGs are designed to end poverty, hunger, AIDS, and discrimination against women and girls.

The creativity, expertise, technology and financial resources from all of society are necessary to achieve the SDGs in every context.

Goal 1

No Poverty

Eradicating poverty in all its forms remains one of the greatest challenges facing humanity. While the number of people living in extreme poverty dropped by more than half between 1990 and 2015, many individuals are still struggling for the most basic human needs.

As of 2015, about 736 million people still lived on less than US$1.90 a day; many lack food, clean drinking water and sanitation. Rapid growth in countries such as China and India has lifted millions out of poverty, but progress has been uneven. Women are more likely to be poor than men because they have less paid work, education, and own less property.

Progress towards the elimination of poverty has also been limited in other regions, such as South Asia and sub-Saharan Africa, which account for 80% of those living in extreme poverty. New threats brought on by climate change, conflict and food insecurity mean even more work is needed to bring people out of poverty.

The SDGs are a bold commitment to finish what we started with the Millenium Development Goals (an earlier iteration of the SDGs), and to end poverty in all forms and dimensions by 2030. This involves targeting the most vulnerable, increasing basic resources and services, and supporting communities affected by conflict and climate-related disasters.

Goal 2

Zero Hunger

The number of undernourished people has dropped by almost half in the past two decades because of rapid economic growth and increased agricultural productivity. Many developing countries that used to suffer from famine and hunger can now meet their nutritional needs. Central and East Asia, Latin America and the Caribbean have all made huge progress in eradicating extreme hunger.

Unfortunately, extreme hunger and malnutrition remain a huge barrier to development in many countries. There are 821 million people estimated to be chronically undernourished as of 2017, often as a direct consequence of environmental degradation, drought and biodiversity loss. Over 90 million children under five are dangerously underweight. Undernourishment and severe food insecurity appear to be increasing in almost all regions of Africa, as well as in South America.

The SDGs aim to end all forms of hunger and malnutrition by 2030, making sure all people–especially children–have sufficient and nutritious food all year. This involves promoting sustainable agriculture, supporting small-scale farmers and equal access to land, technology and markets. It also requires international cooperation to ensure investment in infrastructure and technology to improve agricultural productivity.

Goal 3

Good Health and Well Being

The global community has made great progress against several leading causes of death and disease. Life expectancy has increased dramatically; infant and maternal mortality rates have declined, we’ve turned the tide on HIV, and malaria deaths have halved.

Good health is essential to sustainable development and the 2030 Agenda reflects the complexity and interconnectedness of the two. The 2030 Agenda takes into account widening economic and social inequalities, rapid urbanization, threats to the climate and the environment, the continuing burden of HIV and other infectious diseases, and emerging challenges such as noncommunicable diseases. Universal health coverage will be integral to achieving SDG 3, ending poverty and reducing inequalities. Emerging global health priorities not explicitly included in the SDGs, including antimicrobial resistance, also demand action.

But the world is off-track to achieve the health-related SDGs. Progress has been uneven, both between and within countries. There is a 31-year gap between the countries with the shortest and longest life expectancies. And while some countries have made impressive gains, national averages hide that many are being left behind. Multisectoral, rights-based and gender-sensitive approaches are essential to address inequalities and to build good health for all.

Goal 4

Quality Education

Since 2000, there has been enormous progress in achieving the target of universal primary education. The total enrollment rate in developing regions reached 91 % in 2015, and the worldwide number of children out of school has dropped by almost half. There has also been a dramatic increase in literacy rates, and many more girls are in school than ever before. These are all remarkable successes.

Progress has also been tough in some developing regions due to high levels of poverty, armed conflicts and other emergencies. In Western Asia and North Africa, ongoing armed conflict has seen an increase in the number of children out of school. This is a worrying trend. While Sub-Saharan Africa made the greatest progress in primary school enrollment among all developing regions – from 52% in 1990, up to 78% in 2012 – large disparities still remain. Children from the poorest households are up to four times more likely to be out of school than those of the richest households. Disparities between rural and urban areas also remain high.

Achieving inclusive and quality education for all reaffirms the belief that education is one of the most powerful and proven vehicles for sustainable development. This goal ensures that all girls and boys complete free primary and secondary schooling by 2030. It also aims to provide equal access to affordable vocational training, to eliminate gender and wealth disparities, and achieve universal access to a quality higher education.

Goal 5

Gender Equality

Ending all discrimination against women and girls is not only a basic human right, it’s crucial for a sustainable future; it’s proven that empowering women and girls helps economic growth and development.

UNDP has made gender equality central to its work and we’ve seen remarkable progress in the past 20 years. There are more girls in school now compared to 15 years ago, and most regions have reached gender parity in primary education.

But although there are more women than ever in the labor market, there are still large inequalities in some regions, with women systematically denied the same work rights as men. Sexual violence and exploitation, the unequal division of unpaid care and domestic work, and discrimination in public office all remain huge barriers to gender equality. Climate change and disasters continue to have a disproportionate effect on women and children, as do conflict and migration.

It is vital to give women equal rights, land and property, sexual and reproductive health, and access to technology and the internet. Today there are more women in public office than ever before, but encouraging more women leaders will help achieve greater gender equality.

Goal 6

Clean Water and Sanitation

Water scarcity affects more than 40% of people in the world, an alarming figure that is projected to rise as temperatures do. Although 2.1 billion people have improved water sanitation since 1990, dwindling drinking water supplies are affecting every continent.

More and more countries are experiencing water stress, and increasing drought and desertification is already worsening these trends. By 2050, it is projected that at least one in four people will suffer recurring water shortages.

Safe and affordable drinking water for all by 2030 requires that we invest in adequate infrastructure, provide sanitation facilities, and encourage hygiene. Protecting and restoring water-related ecosystems is essential.

Ensuring universal safe and affordable drinking water involves reaching over 800 million people who lack basic services and improving accessibility and safety of services for over two billion people.

In 2015, 4.5 billion people lacked safely managed sanitation services (with adequately disposed or treated excreta) and 2.3 billion lacked even basic sanitation.

Goal 7

Affordable and Clean Energy

Between 2000 and 2018, the number of people worldwide with electricity increased from 78% to 90%, and the numbers without electricity dipped to 789 million.

Yet as the population continues to grow, so will the demand for cheap energy, and an economy reliant on fossil fuels is creating drastic changes to our climate.

Investing in solar, wind and thermal power, improving energy productivity, and ensuring energy for all is vital if we are to achieve SDG 7 by 2030.

Expanding infrastructure and upgrading technology to provide clean and more efficient energy in all countries will encourage growth and help the environment.

Goal 8

Decent Work and Economic Growth

Over the past 25 years, the number of workers living in extreme poverty has declined dramatically, despite the lasting impact of the 2008 economic crisis and global recession. In developing countries, the middle class now makes up more than 34% of total employment – a number that has almost tripled between 1991 and 2015.

However, as the global economy continues to recover, we are seeing slower growth, widening inequalities, and not enough jobs to keep up with a growing labor force. According to the International Labour Organization, more than 204 million people were unemployed worldwide in 2015.

The SDGs promote sustained economic growth, higher levels of productivity and technological innovation. Encouraging entrepreneurship and job creation are key to this, as are effective measures to eradicate forced labor, slavery and human trafficking. With these targets in mind, the goal is to achieve full and productive employment, and decent work, for all women and men by 2030.

Goal 9

Industry, Innovation, and Infrastructure

Investment in infrastructure and innovation are crucial drivers of economic growth and development. With over half the world population now living in cities, mass transport and renewable energy are becoming ever more important, as are the growth of new industries and information and communication technologies.

Technological progress is also key to finding lasting solutions to both economic and environmental challenges, such as providing new jobs and promoting energy efficiency. Promoting sustainable industries, and investing in scientific research and innovation are all important ways to facilitate sustainable development.

More than 4 billion people still do not have access to the Internet, and 90 % are from the developing world. Bridging this digital divide is crucial to ensure equal access to information and knowledge, as well as foster innovation and entrepreneurship.

Goal 10

Reduced Inequalities

Income inequality is on the rise—the richest 10% have up to 40% of global income whereas the poorest 10 % earn only between 2 to 7%. If we take into account population growth inequality in developing countries, inequality has increased by 11%.

Income inequality has increased nearly everywhere in recent decades, but at different speeds. It’s lowest in Europe and highest in the Middle East.

These widening disparities require sound policies to empower lower income earners, and promote economic inclusion of all regardless of sex, race or ethnicity.

Income inequality requires global solutions. This involves improving the regulation and monitoring of financial markets and institutions, encouraging development assistance and foreign direct investment to regions where the need is greatest. Facilitating the safe migration and mobility of people is also key to bridging the widening divide.

Goal 11

Sustainable Cities and Communities

More than half of us live in cities. By 2050, two-thirds of all humanity—6.5 billion people—will be urban. Sustainable development cannot be achieved without significantly transforming the way we build and manage our urban spaces.

The rapid growth of cities—a result of rising populations and increasing migration—has led to a boom in mega-cities, especially in the developing world, and slums are becoming a more significant feature of urban life.

Making cities sustainable means creating career and business opportunities, safe and affordable housing, and building resilient societies and economies. It involves investment in public transport, creating green public spaces, and improving urban planning and management in participatory and inclusive ways.

Goal 12

Responsible Consumption and Production

Achieving economic growth and sustainable development requires that we urgently reduce our ecological footprint by changing the way we produce and consume goods and resources. Agriculture is the biggest user of water worldwide, and irrigation now claims close to 70% of all freshwater for human use.

The efficient management of our shared natural resources, and the way we dispose of toxic waste and pollutants, are important targets to achieve this goal. Encouraging industries, businesses and consumers to recycle and reduce waste is equally important, as is supporting developing countries to move towards more sustainable patterns of consumption by 2030.

A large share of the world population is still consuming far too little to meet even their basic needs. Halving the per capita of global food waste at the retailer and consumer levels is also important for creating more efficient production and supply chains. This can help with food security, and shift us towards a more resource efficient economy.

Goal 13

Climate Action

There is no country that is not experiencing the drastic effects of climate change. Greenhouse gas emissions are more than 50% higher than in 1990. Global warming is causing long-lasting changes to our climate system, which threatens irreversible consequences if we do not act.

The annual average economic losses from climate-related disasters are in the hundreds of billions of dollars. This is not to mention the human impact of geo-physical disasters, which are 91% climate-related, and which between 1998 and 2017 killed 1.3 million people, and left 4.4 billion injured. The goal aims to mobilize US$100 billion annually by 2020 to address the needs of developing countries to both adapt to climate change and invest in low-carbon development.

Supporting vulnerable regions will directly contribute not only to Goal 13 but also to the other SDGs. These actions must also go hand in hand with efforts to integrate disaster risk measures, sustainable natural resource management, and human security into national development strategies. It is still possible, with strong political will, increased investment, and using existing technology, to limit the increase in global mean temperature to two degrees Celsius above pre-industrial levels, aiming at 1.5°C, but this requires urgent and ambitious collective action.

Goal 14

Life Below Water

The world’s oceans – their temperature, chemistry, currents and life – drive global systems that make the Earth habitable for humankind. How we manage this vital resource is essential for humanity as a whole, and to counterbalance the effects of climate change.

Over three billion people depend on marine and coastal biodiversity for their livelihoods. However, today we are seeing 30% of the world’s fish stocks overexploited, reaching below the level at which they can produce sustainable yields.

Oceans also absorb about 30% of the carbon dioxide produced by humans, and we are seeing a 26% rise in ocean acidification since the beginning of the industrial revolution. Marine pollution, an overwhelming majority of which comes from land-based sources, is reaching alarming levels, with an average of 13,000 pieces of plastic litter to be found on every square kilometer of ocean.

The SDGs aim to sustainably manage and protect marine and coastal ecosystems from pollution, as well as address the impacts of ocean acidification. Enhancing conservation and the sustainable use of ocean-based resources through international law will also help mitigate some of the challenges facing our oceans.

Goal 15

Life on Land

Human life depends on the earth as much as the ocean for our sustenance and livelihoods. Plant life provides 80% of the human diet, and we rely on agriculture as an important economic resource. Forests cover 30% of the Earth’s surface, provide vital habitats for millions of species, and important sources for clean air and water, as well as being crucial for combating climate change.

Every year, 13 million hectares of forests are lost, while the persistent degradation of drylands has led to the desertification of 3.6 billion hectares, disproportionately affecting poor communities.

While 15% of land is protected, biodiversity is still at risk. Nearly 7,000 species of animals and plants have been illegally traded. Wildlife trafficking not only erodes biodiversity, but creates insecurity, fuels conflict, and feeds corruption.

Urgent action must be taken to reduce the loss of natural habitats and biodiversity which are part of our common heritage and support global food and water security, climate change mitigation and adaptation, and peace and security.

Goal 16

Peace, Justice, and Strong Institutions

We cannot hope for sustainable development without peace, stability, human rights and effective governance, based on the rule of law. Yet our world is increasingly divided. Some regions enjoy peace, security and prosperity, while others fall into seemingly endless cycles of conflict and violence. This is not inevitable, and must be addressed.

Armed violence and insecurity have a destructive impact on a country’s development, affecting economic growth, and often resulting in grievances that last for generations. Sexual violence, crime, exploitation and torture are also prevalent where there is conflict, or no rule of law, and countries must take measures to protect those who are most at risk

The SDGs aim to significantly reduce all forms of violence and work with governments and communities to end conflict and insecurity. Promoting the rule of law and human rights are key to this process, as is reducing the flow of illicit arms and strengthening the participation of developing countries in the institutions of global governance.

Goal 17

Partnerships for the Goals

The SDGs can only be realized with strong global partnerships and cooperation. Official Development Assistance remained steady but below target, at US$147 billion in 2017. Yet, humanitarian crises brought on by conflict or natural disasters continue to demand more financial resources and aid. Many countries also require Official Development Assistance to encourage growth and trade.

The world is more interconnected than ever. Improving access to technology and knowledge is an important way to share ideas and foster innovation. Coordinating policies to help developing countries manage their debt, as well as promoting investment for the least developed countries, is vital for sustainable growth and development.

The goals aim to enhance North-South and South-South cooperation by supporting national plans to achieve all the targets. Promoting international trade, and helping developing countries increase their exports is all part of achieving a universal rules-based and equitable trading system that is fair and open and benefits all.

Health Metrics and Health Indicators

Health metrics, or health indicators, are events or characteristics that are measured to estimate and describe the health of a population. A number of health metrics, or health indicators, are commonly used in global health to assess the health needs of populations; to identify risk factors for diseases that contribute to the global burden of disease, to evaluate the impact of interventions on health outcomes; and to monitor changes in health status of various populations over time. These health metrics help to drive the global health agenda and allow the global health community to monitor progress over time. The following sections introduce some of the most common health indicators relevant to your study of global health. 

Life Expectancy at Birth is defined as the average number of years a person can expect to live. The global average is 73 years. Research has shown that this indicator varies greatly according to geography, and tables have been compiled showing averages for different countries, ranging from Lesotho at 50.75 years to Japan at 84.26 years (World Health Organization, n.d.-c).

Infant Mortality refers to the death of an infant in the first year of life, or before his/her first birthday. The infant mortality rate is represented by the number of infant deaths per 1,000 live births. Infant mortality varies greatly by region of birth and is gradually declining. The WHO shows the global probability of dying between birth and age 1 per 1000 live births was 28.13% in 2019, down from 32.32% in 2014. This indicator is consistently higher in males. For example, in 2019, the global probability of dying before age 1 was 30.18% in males compared to 25.93% for females (World Health Organization, 2022a).

Maternal mortality is defined as the death of a woman during pregnancy or within 42 days of termination of pregnancy. The maternal mortality rate is represented by the number of maternal deaths per 100,000 live births. The SDG Target 3.1 is to reduce maternal mortality to less than 70 per 100,000 live births. In 2000 this rate was 339 globally, but decreased to 227 by 2020 (a 34% reduction). A great challenge exists to reach the SDG Target of less than 70, especially in areas like sub-Saharan Africa where the 2020 rate was 545, compared to the lowest rate of 4 in New Zealand and Australia (WHO et al., 2023; World Health Organization, n.d.-d).

The most common cause of death after giving birth is from severe bleeding, or hemorrhage. This and other causes, such as high blood pressure and infections are all largely preventable and treatable (World Health Organization, 2023a, 2023b).

Under-Five Mortality refers to the probability of a child born in a specific year or period dying before reaching the age of five, if subject to the age-specific mortality rates of that period. The under-five mortality rate is expressed as the number of deaths among children under the age of five per 1000 live births. The SDG Target 3.2 is to end preventable deaths under 5 years old. That rate has declined from 93 deaths per 1000 live births in 1990 to 37 in 2020. The highest mortality rates are in sub-Saharan Africa and southern Asia, which regions account for 53% of global live births, but more than 80% of under-five deaths. The leading causes of under-five mortality are infectious diseases, preterm birth complications, birth trauma, and congenital anomalies (Ritchie, 2018; World Health Organization, n.d.-e).

Prevalence is the proportion of a population that has a disease or characteristic at a given time. It is reported as a percentage (cases per 100) or as cases per 10,000 or 100,000, depending on how common the item is in the population (National Institute of Mental Health, n.d.).

Incidence is the number of new cases of a disease or characteristic that develop in a population in a specified time period.

For example, during the COVID-19 pandemic, prevalence was reported as total numbers of cases in the population. A company needed to know the prevalence of COVID-19 in their workforce, to know how many employees were unable to work. In contrast, incidence was reported as new cases diagnosed in a certain week or month. Knowing incidence rates gave healthcare workers an idea of how quickly COVID-19 was spreading.

Disability-Adjusted Life Year (DALY) is a measure of the overall burden of disease. One DALY represents the loss of one year of full health. DALY is calculated by adding years of life lost due to early death plus years lived with a disability due to the disease (World Health Organization, n.d.-b). Knowing the DALYs allows comparison of burdens for different diseases, across countries, between population groups, and over time. Using this measure, cardiovascular disease (393 million DALYs) created more of a global burden than natural disasters (0.96 million DALYs) in 2019 (Roser et al., 2021). Use of the DALY in determining the global health agenda, as opposed to data that considers only premature mortality, is what has drawn attention to health issues like mental health disorders and neglected tropical diseases that have previously been underestimated or underappreciated as global health priorities.

The Human Development Index (HDI) 

(United Nations Development Programme, n.d.-a)

was created to emphasize that people and their capabilities should be the ultimate criteria for assessing the development of a country, not economic growth alone.

The HDI is a summary measure of average achievement in key dimensions of human development: a long and healthy life, being knowledgeable and having a decent standard of living. The HDI is the geometric mean of normalized indices for each of the three dimensions.

The health dimension is assessed by life expectancy at birth. The education dimension is measured by mean years of schooling for adults aged 25 years or older and expected years of schooling for children of school entering age. The standard of living dimension is measured by gross national income per capita. The HDI uses the logarithm of income, to reflect the diminishing importance of income with increasing GNI. The scores for the three HDI dimension indices are then aggregated into a composite index using geometric mean.

The HDI can be used to question national policy choices, asking how two countries with the same level of GNI per capita can end up with different human development outcomes. These contrasts can stimulate debate about government policy priorities.

The HDI simplifies and captures only part of what human development entails. It does not reflect on inequalities, poverty, human security, empowerment, etc. The HDRO provides other composite indices as broader proxy on some of the key issues of human development, inequality, gender disparity, and poverty.

A fuller picture of a country's level of human development requires analysis of other indicators and information presented in the HDR statistical annex.

Global Patterns and Trends

Improvements in public health and reductions in premature mortality achieved in high-income countries since the 20th century provide strong evidence of the effectiveness of large-scale health interventions and health-supportive policies. However, these improvements and public health successes have not been achieved equally around the world. One objective of studying global health is to understand common patterns, or health transitions, that typically accompany economic development. While most high-income countries have completed these health transitions, many low- and middle-income countries remain in various stages of transition. The following sections provide a brief overview of some of the many differences that can be observed in terms of the health status, risk factors, and causes of mortality in high-income vs. low- and middle-income countries, as well as among different age groups, and differences that have been observed globally over time. The Global Burden of Disease is a major global study on the causes of death and disease published in the medical journal The Lancet. It is a leading resource used in global health to monitor health status and one that also facilitates comparisons between countries and populations.

Causes of Death 

(Ritchie et al., 2018)

It is important to understand what is meant by the cause of death and the risk factor associated with a premature death.

In the epidemiological framework of the Global Burden of Disease study each death has one specific cause–“each death is attributed to a single underlying cause–the cause that initiated the series of events leading to death.”

This is different from the deaths that happened due to risk factors. These deaths are an estimation of the reduction of the number of deaths that would be achieved if the risk factors to which a population is exposed were eliminated or reduced to an optimal, healthy level.

What do people die from?

56 million people died in 2017. What did they die from?

Non-communicable diseases (NCDs) not only dominate mortality figures at a global level, but also account for the majority of deaths in high-income countries.

Deaths from causes such as infectious disease, malnutrition, nutritional deficiencies, neonatal, and maternal deaths are common – and in some cases dominant – across low- and middle-income nations. In Kenya, for example, the leading cause of death remains diarrheal diseases. In South Africa and Botswana, the leading cause of death is HIV/AIDS. In high-income countries however the share of deaths caused by these is very low.

Death rates related to disease, illness and other health factors tend to change relatively slowly over time. While death rates may fall or decline from year-to-year as part of a general trend, dramatic changes in such deaths are typically rare. Natural disaster and terrorism-related deaths are an important exception to this rule, as they can vary significantly between countries.

Globally, the share of deaths from infectious diseases are declining; a larger share of people are dying from NCDs.

At a global level we see that the majority of deaths are caused by non-communicable diseases (NCDs). Collectively, NCDs account for more than 73% of global deaths. As the world is making progress in the fight against many infectious diseases, and as populations age, we expect that NCDs will become increasingly dominant as the cause of death.

Causes of Death by Age

In 2017, there were 56.5 million deaths globally; just over half of these were people who were 70 years or older; 26% were between 50 and 69 years old; 13% were between 15 and 49; only 1% were older than 5 and younger than 14; and almost 9% were children under the age of 5.

The age at which people die has changed significantly since 1990. Fewer people die at a young age. In 1990 nearly one-quarter of all deaths were in children younger than 5. In 2019, this had declined to just under 9%. In contrast, the share of deaths in the over-70s age bracket has increased from a third to half of all deaths over this period.

Causes of Deaths of Children Younger Than 5

Through the combination of neonatal (newborn infants less than 28 days old) disorders, infections and congenital (from birth) defects, we see that the largest share of deaths in under-5s arises from complications at birth or in the first few weeks of life. Under-5s are also highly susceptible to lower respiratory infections, infectious diseases, diarrheal infections, malnutrition, and nutritional deficiencies.

Death rates in under-5s are typically much lower in high-income countries, and the nature of these deaths is different from lower incomes. In the United Kingdom, for example, child deaths tend to be highly dominated by neonatal complications. Deaths from infectious and diarrheal diseases and malnutrition are very low. In contrast, infectious diseases and nutritional deficiencies are large causes of death in lower-income countries.

Causes of Deaths for Children Between 5 and 14

Globally, deaths in the 5-14 year old age bracket account for a small percentage of the total deaths (1-2%).

There are six dominant causes of deaths in this age category. The leading causes globally in 5-14 year olds are road accidents, cancers, and malaria. Lower respiratory infections, HIV/AIDS, diarrheal diseases, and drowning are all dominant causes typically in the range of 40,000-50,000 deaths in 2017.

Again, this distribution varies by country. In the United States, for example, cancers are the leading cause of death. In India, it’s diarrheal diseases; in Bangladesh and China, it’s drowning; and in South Africa, it is HIV/AIDS.

Causes of Deaths for 15 to 49 Year Olds

In the 15 to 49 years old category, we see that non-communicable diseases (NCDs) begin to become dominant. Globally, the leading cause of death in this age group is cardiovascular disease, followed by cancers which both account for more than one million deaths. Road accidents, HIV/AIDS, and suicide are all significant within this group.

For some countries, such as South Africa, by far the dominant cause of death is HIV/AIDS in 15 to 49 year olds. In a number of countries, in particular across Latin America, homicide is the dominant cause of death for people between 15-49 years old.

Causes of Deaths for 50 to 69 Year Olds

In 50 to 69 year olds, non-communicable diseases (NCDs) are strongly dominant: cardiovascular disease, cancers, respiratory disease, and diabetes are the top causes. With the exception of HIV/AIDS and tuberculosis, which for some countries climb into the top causes, the global variability in death causes for 50-69 year olds is much lower than that of younger age categories.

Causes of Deaths for People Who Were Older than 69 years

For the oldest age category (70 years and older), non-communicable diseases (NCDs) still dominate, however other causes of death including Alzheimer’s/dementias, and diarrheal diseases also become dominant. Diarrheal diseases remain within the few leading causes of deaths in 70+ year olds for many low-income countries, despite being relatively low in higher income countries.

Risk Factors for Death

Risk factors can be grouped into four broad categories: behavioral risks, environmental risks, occupational risks, and metabolic risks.

The Number of Deaths by Risk Factor

Globally, there are several dominant risk factors for death: notably, those related to dietary and activity lifestyle factors (including blood pressure, physical activity, body-mass index, blood sugar, and dietary intake); smoking; air pollution (both outdoor and indoor); environmental factors including clean water and sanitation; and safe sex (for the prevention of HIV/AIDS).

For most high-income countries, the dominant risk factors are those related to healthy diets, smoking, and alcohol intake. Other risk factors such as clean water, sanitation, and child wasting or stunting are very low. In low-income countries the inverse is true: in Sierra Leone for example, the top risk factors include child wasting, household air pollution, unsafe water source, poor sanitation, and the lack of access to handwashing facilities. For countries where HIV/AIDS is a major health burden, such as South Africa and Kenya, unsafe sex is the top risk factor.

Top 10 Causes of Death 

(World Health Organization, 2020)

In 2019, the top 10 causes of death accounted for 55% of the 55.4 million deaths worldwide.

The top global causes of death, in order of total number of lives lost, are associated with three broad topics: cardiovascular (ischaemic heart disease, stroke), respiratory (chronic obstructive pulmonary disease, lower respiratory infections), and neonatal conditions – which include birth asphyxia and birth trauma, neonatal sepsis and infections, and preterm birth complications.

Causes of death can be grouped into three categories: communicable (infectious and parasitic diseases and maternal, perinatal and nutritional conditions), noncommunicable (chronic) and injuries.

Leading causes of death globally

At a global level, 7 of the 10 leading causes of deaths in 2019 were noncommunicable diseases. These seven causes accounted for 44% of all deaths or 80% of the top 10. However, all noncommunicable diseases together accounted for 74% of deaths globally in 2019.

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The world’s biggest killer is ischaemic heart disease, responsible for 16% of the world’s total deaths. Since 2000, the largest increase in deaths has been from ischaemic heart disease, rising by more than 2 million to 8.9 million deaths in 2019. Stroke and chronic obstructive pulmonary disease are the 2nd and 3rd leading causes of death, responsible for approximately 11% and 6% of total global deaths respectively.

Lower respiratory infections remained the world’s most deadly communicable disease, ranked as the 4th leading cause of death. However, the number of deaths has gone down substantially: In 2019, it claimed 2.6 million lives, 460,000 fewer than in 2000.

Neonatal conditions are ranked 5th. However, deaths from neonatal conditions are one of the categories for which the global decrease in deaths in absolute numbers over the past two decades has been the greatest: these conditions killed 2 million newborns and young children in 2019, 1.2 million fewer than in 2000.

Deaths from noncommunicable diseases are on the rise. Trachea, bronchus and lung cancers deaths have risen from 1.2 million to 1.8 million, and are now ranked 6th among leading causes of death.

In 2019, Alzheimer’s disease and other forms of dementia ranked as the 7th leading cause of death. Women are disproportionately affected. Globally, 65% of deaths from Alzheimer’s and other forms of dementia are women.

One of the largest declines in the number of deaths is from diarrhoeal diseases, with global deaths falling from 2.6 million in 2000 to 1.5 million in 2019.

Diabetes has entered the top 10 causes of death, following a significant percentage increase of 70% since 2000. Diabetes is also responsible for the largest rise in male deaths among the top 10, with an 80% increase since 2000.

Other diseases which were among the top 10 causes of death in 2000 are no longer on the list. HIV/AIDS is one of them. Deaths from HIV/AIDS have fallen by 51% during the last 20 years, moving from the world’s 8th leading cause of death in 2000 to the 19th in 2019.

Kidney diseases have risen from the world’s 13th leading cause of death to the 10th. Mortality has increased from 813,000 in 2000 to 1.3 million in 2019.

Leading causes of death by income group

On their page, World Bank Country and Lending Groups, the World Bank classifies the world's economies into four income groups based on their gross national income – low, lower-middle, upper-middle, and high.

Low-income countries

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People living in a low-income country are far more likely to die of a communicable disease than a noncommunicable disease. Despite the global decline, six of the top 10 causes of death in low-income countries are communicable diseases.

Malaria, tuberculosis and HIV/AIDS all remain in the top 10. However, rates for all three are falling significantly. The biggest decrease has been for HIV/AIDS, with 59% fewer deaths in 2019 than in 2000.

Diarrheal diseases are more significant as a cause of death in low-income countries: they rank in the top 5 causes of death for this income category. Nonetheless, diarrheal diseases are decreasing in low-income countries, representing the second biggest decrease in fatalities among the top 10 (231,000 fewer deaths).

Deaths due to chronic obstructive pulmonary disease are particularly infrequent in low-income countries compared to other income groups. It does not appear in the top 10 causes of death for low-income countries, yet ranks in the top 5 for all other income groups.

Lower-Middle-Income countries

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Lower-middle-income countries have the most varied top 10 causes of death: five noncommunicable, four communicable, and one injury. Diabetes is a rising cause of death in this income group: it has moved from the 15th to 9th leading cause of death, and the number of deaths from this disease has nearly doubled since 2000.

As a top 10 cause of death in this income group, diarrheal diseases remain a significant challenge. However, the biggest decrease in absolute deaths has been observed for diarrheal diseases, falling from 1.9 million to 1.1 million between 2000 and 2019. The biggest increase in absolute deaths is from ischaemic heart disease, rising by more than 1 million to 3.1 million since 2000. HIV/AIDS, has seen the biggest decrease in rank among the top causes of death, moving from 8th in 2000 to 15th.

Upper-Middle-Income Countries

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In upper-middle-income countries, there has been a notable rise in deaths from lung cancer, which have increased by 411,000 since 2000; this is more than double the increase in deaths from lung cancer from all three other country income groups combined. In addition, stomach cancer features highly in upper-middle-income countries compared to the other income groups. This is the only income group where stomach cancer ranks in the top 10 causes of death.

One of the biggest decreases in terms of absolute number of deaths is for chronic obstructive pulmonary disease, which has fallen by nearly 264,000 deaths to 1.3 million deaths. However, deaths from ischemic heart disease have increased by more than 1.2 million, the largest rise in any income group in terms of absolute number of deaths from this cause.

There is only one communicable disease (lower respiratory infections) in the top 10 causes of death for upper-middle-income countries. Notably, there has been a 31% decrease in deaths from suicide since 2000 in this income category, decreasing to 234,000 deaths in 2019.

High-Income Countries

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In high-income countries, deaths are increasing for all top 10 causes of death except two. Ischaemic heart disease and stroke are the only causes of death in the top 10 for which the total numbers have gone down between 2000 and 2019. Deaths from heart disease decreased by 16% (or 327, 000 deaths) and deaths from stroke have decreased by 21% (or 205,000 deaths) between 2000 and 2019.

High-income is the only income group in which there have been decreasing numbers of deaths from these two diseases. Nonetheless, ischaemic heart disease and stroke have remained in the top three causes of death for this income category, with a combined total of over 2.5 million fatalities in 2019. In addition, deaths from hypertensive heart disease are rising. Reflecting a global trend, this disease has risen from the 18th leading cause of death to the 9th.

Deaths due to Alzheimer’s disease and other dementias have increased, overtaking stroke to become the second leading cause of death in high-income countries, and being responsible for the deaths of 814,000 people in 2019. And, as seen with upper-middle-income countries, only one communicable disease (lower respiratory infections) appears in the top 10 causes of death.

Why do we need to know the reasons people die?

It is important to know why people die to improve how people live. Measuring how many people die each year helps to assess the effectiveness of our health systems and direct resources to where they are needed most. For example, mortality data can help focus activities and resource allocation among sectors such as transportation, food and agriculture, and the environment as well as health.

COVID-19 has highlighted the importance for countries to invest in civil registration and vital statistics systems to allow daily counting of deaths, and direct prevention and treatment efforts. It has also revealed inherent fragmentation in data collection systems in most low-income countries, where policy-makers still do not know with confidence how many people die and of what causes.

The routine collection and analysis of high-quality data on deaths and causes of death, as well as data on disability, disaggregated by age, sex and geographic location, is essential for improving health and reducing deaths and disability across the world.

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Glossary

• Public health = health of a population in a specific community or country
• International health = emphasis on health issues in developing countries
• Global health = health for all people regardless of national boundaries.
• health disparities