Learning Objectives
By the end of this section, you should be able to:
- Define social epidemiology
- Apply theories of social epidemiology to an understanding of global health issues
- Differentiate high-income and low-income nations
Social epidemiology is the study of the causes and distribution of diseases. Social epidemiology can reveal how social problems are connected to the health of different populations. These epidemiological studies show that the health problems of high-income nations differ from those of low-income nations, but also that diseases and their diagnosis are changing. Cardiovascular disease, for example, is now the both most prevalent disease and the disease most likely to be fatal in lower-income countries. And globally, 70 percent of cardiovascular disease cases and deaths are due to modifiable risks (Dagenais 2019).
Some theorists differentiate among three types of countries: core nations, semi-peripheral nations, and peripheral nations. Core nations are those that we think of as highly developed or industrialized, semi-peripheral nations are those that are often called developing or newly industrialized, and peripheral nations are those that are relatively undeveloped. While the most pervasive issue in the U.S. healthcare system is affordable access to healthcare, other core countries have different issues, and semi-peripheral and peripheral nations are faced with a host of additional concerns. Reviewing the status of global health offers insight into the various ways that politics and wealth shape access to healthcare, and it shows which populations are most affected by health disparities.
Health in High-Income Nations
Obesity, which is on the rise in high-income nations, has been linked to many diseases, including cardiovascular problems, musculoskeletal problems, diabetes, and respiratory issues. According to the Organization for Economic Cooperation and Development (2011), obesity rates are rising in all countries, with the greatest gains being made in the highest-income countries. The United States has the highest obesity rate at 42 percent; some of these people are considered severely obese, which occurs in 9 percent of U.S. adults (Hales 2020).
Wallace Huffman and his fellow researchers (2006) contend that several factors are contributing to the rise in obesity in developed countries:
- Improvements in technology and reduced family size have led to a reduction of work to be done in household production.
- Unhealthy market goods, including processed foods, sweetened drinks, and sweet and salty snacks are replacing home-produced goods.
- Leisure activities are growing more sedentary, for example, computer games, web surfing, and television viewing.
- More workers are shifting from active work (agriculture and manufacturing) to service industries.
- Increased access to passive transportation has led to more driving and less walking.
Obesity and weight issues have significant societal costs, including lower life expectancies and higher shared healthcare costs.
While ischemic heart disease is the single most prevalent cause of death in higher-income countries, cancers of all types combine to be a higher overall cause of death. Cancer accounts for twice as many deaths as cardiovascular disease in higher-income countries (Mahase 2019).
Health in Low-Income Nations
In peripheral nations with low per capita income, it is not the cost of healthcare that is the most pressing concern. Rather, low-income countries must manage such problems as infectious disease, high infant mortality rates, scarce medical personnel, and inadequate water and sewer systems. Due to such health concerns, low-income nations have higher rates of infant mortality and lower average life spans.
One of the biggest contributors to medical issues in low-income countries is the lack of access to clean water and basic sanitation resources. According to a 2014 UNICEF report, almost half of the developing world’s population lacks improved sanitation facilities. The World Health Organization (WHO) tracks health-related data for 193 countries, and organizes them by region. In their 2011 World Health Statistics report, they document the following statistics:
- Globally in 2019, the rate of mortality for children under five was 38 per 1,000 live births, which is a dramatic change from previous decades. (In 1990, the rate was 93 deaths per 1,000 births (World Health Organization 2020.)) In low-income countries, however, that rate is much higher. The child mortality rate in low-income nations was 11 times higher than that of high-income countries—76 deaths per 1,000 births compared to 7 deaths per 1,000 births (Keck 2020). To consider it regionally, the highest under-five mortality rate remains in the WHO African Region (74 per 1000 live births), around 9 times higher than that in the WHO European Region (8 per 1000 live births) (World Health Organization 2021).
- The most frequent causes of death in children under five years old are pneumonia, diarrhea, congenital anomalies, preterm birth complications, birth asphyxia/trauma, and malaria, all of which can be prevented or treated with affordable interventions including immunization, adequate nutrition, safe water and food and quality care by a trained health provider when needed.
The availability of doctors and nurses in low-income countries is one-tenth that of nations with a high income. Challenges in access to medical education and access to patients exacerbate this issue for would-be medical professionals in low-income countries (World Health Organization 2011).