12.2 Epidemiology and Disparities - Social Stratification

MCAT Behavioral Sciences Review - Kaplan Test Prep 2021–2022

12.2 Epidemiology and Disparities
Social Stratification


After Chapter 12.2, you will be able to:

· Identify the causes of Waitzkin’s “second sickness”

· Explain why women are more likely to have better health profiles than men

· Describe the links between class, ethnicity, and healthcare disparities

An old saying intones that Your health is your wealth. This same correlation certainly holds true in reverse: the wealthier tend to have better health and better access to healthcare. Wherever there is low social capital, high urban degradation, interpersonal violence, and low social trust, the social environment is poor, and there is less protection against disease. As a result, class gradients often increase. Poor health conditions and lower life expectancy, as shown in Figure 12.6, are some of the many consequences of social stratification. Low-income groups are significantly worse off than the middle or upper classes when it comes to health disparities, meaning they tend to be sicker than others. Social epidemiology is a branch of epidemiology that studies the ways in which health and disease correlate to social advantages and disadvantages. Image

Figure 12.6. Life Expectancy at Birth, 2005—2010

To understand health statistics, it is important to define a few epidemiological terms. Incidence is defined as the number of new cases of an illness per population at risk in a given amount of time; for example, the number of new cases of lung cancer per 1000 at-risk people per year. Prevalence is a measure of the number of cases of an illness overall—whether new or chronic—per population in a given amount of time; for example, the number of people with new or chronic lung cancer per 1000 people per year. Health statistics are also given in terms of morbidity and mortality. Morbidity is the burden or degree of illness associated with a given disease, while mortality refers to deaths caused by a given disease.

Key Concept

Epidemiology statistics:

· Incidence = new cases / population at risk / time

· Prevalence = total cases / total population / time

Note that incidence is relative to the population at risk, not the total population; if you already have the illness, you are no longer at risk!


Science has clearly demonstrated that poor environmental and social factors negatively impact health. This correlation was first demonstrated in the nineteenth century through public health efforts. One landmark example linking geography with disease was John Snow’s investigation of a cholera outbreak in London in 1854. Snow tracked cases of cholera on a map, as shown in Figure 12.7, and was able to deduce that a water pump in the neighborhood was causing the spread of the infectious agent (a bacterium called Vibrio cholerae).

ImageFigure 12.7. John Snow’s Map of Disease Cases during the 1854 Cholera Outbreak in LondonBy tracing the geography of the disease, Snow deduced that a water pump was responsible for cholera transmission.

Health is dependent not only on geography, but also on social and economic factors. Over time, socioeconomic improvements lead to greater general health in the population, and the best health outcomes are generally seen in egalitarian societies. However, despite the ambitions of the modern welfare state (the system of government that protects the health and well-being of its citizens), the Black Report of 1980 showed that class differences in health still exist, with professional groups having longer life expectancies than working-class people. Howard Waitzkin described this outcome as the second sickness, which is an exacerbation of health outcomes caused by social injustice. As the Centers for Disease Control and Prevention (CDC) have shown, low-income groups are more likely to have poorer health, be uninsured, and die younger than middle- or upper-class adults. Poverty, in combination with a culture of inequality, leads to worse health outcomes, and this effect runs across gender, age, and racial and ethnic boundaries. For example, low-income women are more likely to deliver babies with low birth weights, thereby placing these babies at risk for numerous physical and cognitive problems in life. Similarly, poor racial and ethnic minorities have lower life expectancies. Members of the lower class, overall, are four times more likely to view themselves in worse health compared with affluent groups. Low-income groups are much more likely to develop life-shortening diseases such as lung cancer, diabetes, heart disease, and other degenerative illnesses. These groups are also more likely to commit suicide and die from homicide in comparison to wealthier adults. The infant mortality rate among the poor is also much higher; in some populations of the United States, the infant mortality rate can approximate that of developing countries. However, because of the correlation between poverty and racial and ethnic minorities, many of these characteristics apply to particular ethnic groups more than others.

When it comes to health and illness among racial and ethnic minorities, Asian Americans and Pacific Islanders have some of the best health profiles. Reports illustrate that, in comparison to white Americans, these groups have a lower rate of death associated with cancer, heart disease, diabetes, and infant mortality. African Americans appear to have a worse health profile in comparison to white Americans, showing higher rates of death linked to cancer, heart disease, diabetes, drug and alcohol use, infant mortality, and HIV/AIDS. African American infants have twice the infant mortality rate of white infants. Specifically, African American males have the lowest life expectancy of any racial or gender category. Latinos or Hispanic Americans have a mixed profile in comparison to white Americans, in that they have lower mortality rates attributable to cancer, heart disease, and infant mortality, but higher mortality rates attributable to diabetes, alcohol and drug use, and HIV/AIDS. Hispanics also have a high mortality rate from influenza, pneumonia, and accidents. Native Americans are also mixed in this regard, showing higher rates of death from diabetes, alcohol and drug use, and infant mortality, but lower mortality rates compared to white Americans from cancer, heart disease, and HIV/AIDS. Native Americans also show some of the highest rates of death by suicide in comparison to the general population. This group also has some of the highest mortality rates linked to diabetes compared to any racial category.

MCAT Expertise

The MCAT will not expect you to be able to rattle off the relative rates of these illnesses across racial groups, but a sensitivity to these differences between groups may be important in passages related to sociology and public health.

Key Concept

Low-income groups, especially racial and ethnic minorities, have an overall worse health profile in terms of morbidity and mortality rates.

When it comes to gender-related health disparities, most statistical information shows that females have better health profiles than males. This trend is true throughout the world. Female life expectancy has been consistently higher than male life expectancy since records began. While the gap in life expectancy is beginning to narrow in the United States, most countries still have higher life expectancies for female citizens than male citizens, as shown in Figure 12.8.

ImageFigure 12.8. Male and Female Life Expectancies by Region and CountryNote that female life expectancies are almost universally higher than male life expectancies. Based on data from the CIA World Factbook.

Mortality rates from heart disease, cancer, chronic lower respiratory diseases, and diabetes are higher for males than females. Men are also three times more likely than women to die from accidents, suicide, and homicide. Males are far less likely to seek medical attention than females. Men, especially those raised to have hypermasculine behaviors, may try to “tough it out” rather than go to a doctor. When men do seek healthcare, they are less likely to comply with medical instructions or adhere to medical advice.

While women show better mortality rates, this is not the case when it comes to morbidity rates for certain acute and chronic diseases. More women than men suffer from infectious and parasitic diseases, digestive problems, respiratory conditions, high blood pressure (hypertension), arthritis, diabetes, and inflammatory bowel diseases (colitis). Women tend to suffer more from illnesses and disabilities than men, but their conditions are less often life threatening.

Key Concept

In comparison to females, males tend to have worse mortality rates. However, women have higher morbidity rates. Differences in male and female health profiles are both biologically and sociologically determined, the latter being the result of risk-taking behavior, hypermasculinity, and dangerous employment.

The reasons that men tend to have lower life expectancy rates are both sociological and biological. Sociologically, men are considered to be bigger risk takers, and therefore more likely to expose themselves to accidents and unintentional injuries. This is especially true of young men. Men are also more likely to be employed in dangerous jobs, such as the police force, steel industry, and coal mining. Men also have higher rates of alcohol use, speeding, and participation in potentially violent sports. Biologically speaking, men are at a disadvantage from infancy onward. Throughout life, men are more likely to come down with diseases that are life threatening.


While the United States has one of the most advanced healthcare systems in the world, quality healthcare and services are not always extended to all. Like many institutions, quality healthcare favors those in higher social classes. Many people are frustrated by the way healthcare is delivered in the United States, especially with regard to health insurance. Further, the healthcare system of the United States is one of the few among industrialized nations that is not organized and planned by a central (governmental) system.

Passage of the Affordable Care Act (ACA) in 2010 was an attempt in the United States to increase coverage and affordability of insurance for all Americans, and also to reduce the overall costs of healthcare. Medicare and Medicaid are also programs that attempt to increase access to healthcare in the United States. Medicare covers patients over the age of 65, those with end-stage renal disease, and those with amyotrophic lateral sclerosis (ALS). Medicaid covers patients who are in significant financial need. However, disadvantaged groups, especially poor Americans, are still affected by disparities in healthcare both in terms of access and quality. Even those individuals who have Medicare or Medicaid may lack access, as many physicians will not accept such public insurance programs. Additionally, some doctors will not open practices in low-income neighborhoods, making access even harder for populations with low socioeconomic status. Consequently, individuals in the lower class are less likely to seek medical assistance until they are seriously ill; by then, intervention may be too late.

Key Concept

Medicare covers patients over 65, those with end-stage renal disease, and those with amyotrophic lateral sclerosis (ALS). Medicaid covers patients in significant financial need.

Some of the primary reasons low-income groups have higher mortality rates include poor access to quality medical care, poor nutrition, and feeling less in control of life circumstances. The poor are more likely to smoke and be overweight or obese; they are less likely to engage in physical activity. In addition to socioeconomic status, race and ethnicity can create barriers to care. In race-concordant patient-physician relationships, the patient and physician are of the same race, whereas they are of difference races in race-discordant relationships. Sometimes, culture and non-native language are viewed as contributors to pathology because they can act as obstacles to diagnosis and treatment. Also, despite efforts to systemically address unequal treatment of minority populations by physicians, there are still inequalities and disparities in treatment relative to race and ethnicity over a wide range of medical specialties. In other words, minorities and low-income groups tend to face greater barriers to care, and poorer quality of care when they receive it. To be specific, it has been demonstrated that African Americans, Asian Americans, Native Americans, and Hispanics receive worse care than white Americans.

Quality of preventative care, acute treatment, and chronic disease management also differ regionally. States in New England and the Mid-Atlantic are shown to be in the top quartile of healthcare quality while states in the South are in the bottom quartile.

Outside of race and ethnicity, other identifiable characteristics may have a large impact on how patients are treated by their providers. One of the most common biases is discrimination against overweight and obese patients. This bias can apply to any overweight individual, regardless of socioeconomic status, gender, age, and racial and ethnic background, although there is a higher prevalence of obesity in low-income groups. Doctors are less likely to recommend effective weight loss programs to obese patients, sometimes based on the flawed assumption that obese patients lack the willpower to effectively lose weight. This, in turn, damages the trust necessary to form a strong doctor—patient relationship. As a result, overweight and obese patients are more likely than normal-weight patients to switch doctors repeatedly. When one does not have a consistent primary care doctor, continuity of care is nearly nonexistent. Additionally, overweight or obese patients are less likely to have quality preventative care and screenings, including screenings for breast and colon cancer.

In terms of gender, women tend to be favored by the healthcare system. As a whole, women tend to fare better when it comes to accessing healthcare, largely because women are more likely to be insured. Women tend to utilize healthcare services more than men, with more examinations, blood pressure checks, lab tests, drug prescriptions, and physician visits per year. Women also receive more services per visit than men do. Healthcare use is likely more common among women due to higher morbidity rates among women for many illnesses, thereby facilitating the need to seek medical attention. On the other hand, women are more likely to be delayed or unable to obtain necessary medical care, dental care, and prescription medicines. Also, for LGBT men and women, discrimination and decreased access to healthcare are quite common, largely due to remaining prejudices and homophobia.

MCAT Concept Check 12.2:

Before you move on, assess your understanding of the material with these questions.

1. What is Waitzkin’s second sickness?

2. What is the relationship between class, ethnicity, and health?

3. Why are women more likely to have better health profiles than men?

4. What are some of the factors that contribute to healthcare disparities between classes?