Chapter 3 Social Epidemiology

Chapter 3: Social Epidemiology

Learning Objectives

• Define social epidemiology and delineate research techniques used by epidemiologists.

• Stages of Epidemiological Transition: Identify and describe five major stages.

• Health Performance Analysis: Explain the U.S. performance in life expectancy and infant mortality compared to other countries.

• Social Factors Influencing Health: Discuss how social class, race, and gender affect life expectancy, infant mortality, and morbidity in the U.S.

• Evolving Definition of Disability: Describe how the perception of "disability" has transformed over the past 20 years and identify social factors impacting disability risks.

Overview of Social Epidemiology

• Definition: Epidemiology studies the incidence, causation, distribution, and control of diseases.

• Historical Focus: Early epidemiology emphasized microorganisms but gradually adapted to include social and cultural variables.

• Social Epidemiology Focuses on: Understanding how social factors influence disease and impairments.

Role of Epidemiologists

• Distribution Studies: Epidemiologists investigate who is affected, when, and where, akin to detectives examining patterns in health.

• Social Etiology: They aim to understand the causes and spread of diseases, identifying at-risk populations based on social, economic, and environmental factors.

Methods of Data Gathering

• Data Sources:

  • Examination of medical records from various institutions (e.g., hospitals, schools).

  • Conducting systematic health examinations.

  • Administering health-focused surveys.

  • Implementing controlled experimentation.

Health Surveillance Organizations

• World Health Organization (WHO):

  • Based in Geneva, monitors global health trends, provides technical support, and establishes health protocols.

  • Website: WHO

• Centers for Disease Control and Prevention (CDC):

  • Based in Atlanta, monitors U.S. health conditions and implements systematic disease responses.

  • Website: CDC

Stages of Epidemiological Transition

• Five Major Stages:

  1. Age of Pestilence and Famine

  2. Age of Receding Pandemics

  3. Age of Degenerative and Human-Made Diseases

  4. Age of Delayed Degenerative Diseases

  5. Age of Obesity and Inactivity

Re-emergence of Infectious Diseases

• Threats to Population Health:

  1. Emergence of new infectious diseases.

  2. Declining treatment efficacy for existing diseases.

  3. Increasing resistance of infectious diseases to antibiotics (e.g., TB, syphilis).

• Causes for Emergence:

  • Population growth, travel, climate change, habitat loss, and wildlife trade.

Social Etiology of Disease

• Etiology: Understanding multiple factors influencing disease emergence, including:

  • Disease agents

  • Environmental characteristics

  • Demographic factors and lifestyle

• Chronic Diseases: They often have multiple causes and long latency periods, complicating their tracing back to specific influences.

Social Determinants of Health

• Health Influences: One’s social position significantly affects health outcomes, structured through:

  • Fundamental causes: Socioeconomic status (SES), social inequality, community characteristics.

  • Proximate risk factors: Behaviors such as diet, exercise, and substance use.

Fundamental Causes and Proximate Risk Factors

• Positive Effects of Education: Higher education levels are linked to better health behaviors, employment opportunities, and access to healthcare.

• Health Disparities: Education appears to lower smoking rates and increase exercise, alongside generally improved health outcomes.

Life Expectancy and Mortality

• Global Life Expectancy: Average of 70 years, with the U.S. at 79.7 years, affected by:

  • High mortality before 50 due to drug overdoses, violence, and accidents.

Mortality Rates and Trends

• Crude Death Rate (CDR): Ratio of deaths per 1,000 people; U.S. CDR in 2015 was 8.2.

• Historical Trends: Significant decline in mortality rates since 1900, especially among women.

Infant Mortality

• Decline in Rates: Dropped from 29.2/1,000 live births in 1950 to 5.9 in 2015 due to various health advancements.

• Major Causes: Low birth weight and social factors such as maternal age and prenatal care access.

Maternal Mortality

• Definitions and Trends: MMR increased in the U.S. due to complications like obesity and a rise in Cesarean births.

• Disparities: Higher rates among Black women and those with lower education and marital status.

Morbidity

• Definition: Includes disease, impairment, and accident prevalence; assessed using incidence and prevalence metrics.

• Sociodemographic Variations: Children face morbidity from poor diet and violence, while elderly health improves through better access to care.

SES and Health

• Impacts on Health: Individuals in poverty are more likely to experience unsafe living conditions and engage in unhealthy behaviors.

• Cycle of Poverty: Health disadvantages persist across generations.

Racial and Ethnic Disparities

• Health Outcomes: Higher morbidity for Black populations compared to Whites; economic adversity and discrimination exacerbate health hardships.

Gender Differences in Morbidity

• Five Contributing Factors: Biological risks, acquired risks, psychosocial aspects, health behavior reporting, and prior healthcare experiences.

Changing Views on Disability

• Traditional vs. Contemporary Views: Disability definitions have shifted from physical impairments to a recognition of social context and accommodation needs.

Social Factors Affecting Disability

• Demographic Disparities: Higher disability rates among Blacks and Hispanics, women, less-educated individuals, and those in lower-income brackets.