Public Health Concepts: Putting the 'Public' into Health

PHLT 301 Public Health Concepts

Session 4

Texas A&M University, ATM School of Public Health

But First…

Revisiting Previous Concepts

• Acknowledgment to revisit key concepts from the last session to ensure a strong foundational understanding for the current topics. This reinforces learning by connecting new information with previously discussed vital rates, demographic trends, and the initial stages of disease patterns.

Key Questions

Poll Everywhere Question

1. The majority of leading causes of death in the U.S. are often associated with chronic, non-communicable diseases, a pattern characteristic of later stages of epidemiologic transition. In earlier stages, disease outbreaks would still occur, but usually not widespread, and the overall crude death rate began to drop as public health measures and sanitation improved, shifting the burden from infectious diseases to other causes.

Vital Rates and Epidemiological Transition

Key Definitions

• Vital Rates: These are crucial statistical measures, such as birth rates and death rates, which provide essential quantitative information on the health status and demographic structure of a population. They are fundamental for public health planning and policy formation.

• Epidemiologic Transition: This is a theoretical model describing a significant shift in the dominant disease patterns within a population as it undergoes socioeconomic development. It moves from a prevalence of infectious and parasitic diseases with high mortality to chronic, degenerative diseases as the primary causes of death, typically accompanied by declining mortality and increasing life expectancy.

Stages of Epidemiologic Transition:

1. Pestilence and Famine: Characterized by high and fluctuating death rates, primarily due to epidemics, famines, and infectious diseases, leading to low and variable life expectancy.

2. Receding Pandemics: Marked by a decline in the frequency and impact of infectious disease epidemics, leading to a drop in the crude death rate and an increase in life expectancy. Improvements in sanitation, nutrition, and medical interventions begin to have an effect.

3. Degenerative and Man-Made Diseases: During this stage, infectious diseases are largely controlled, and chronic, non-communicable diseases (e.g., heart disease, cancer, stroke) become the predominant causes of death. Lifestyle factors and environmental exposures play a greater role.

4. Delayed Degenerative Diseases and Emerging Infections (Hybristic): This stage reflects further increases in life expectancy due to advancements in medical technology and healthcare, allowing people to live longer with chronic conditions. However, it also sees the emergence or re-emergence of infectious diseases, often linked to globalization, antimicrobial resistance, and environmental changes.

Crude Birth and Death Rates

• Crude Birth Rate (CBR): Defined as the number of live births occurring among a population of a given geographical area during a given year, per $1,000$ mid-year total population. It's calculated as $(Number of live births / Mid-year population) imes 1,000$.

• Crude Death Rate (CDR): Defined as the number of deaths occurring among a population of a given geographical area during a given year, per $1,000$ mid-year total population. It's calculated as $(Number of deaths / Mid-year population) imes 1,000$.

• Natural Increase: This is the difference between the crude birth rate and the crude death rate. A positive natural increase indicates population growth, while a negative value suggests population decline, assuming no net migration occurs.

Stages of Demographic Transition

1. Early (High Stationary/Early Expanding): Characterized by high birth rates and high, but declining, death rates, leading to moderate population growth in the early phase and rapid growth in the later phase as death rates fall more sharply.

2. Late (Late Expanding): Marked by declining birth rates and continued low death rates, resulting in slower population growth as the gap between births and deaths narrows.

3. Post-Transition (Low Stationary/Declining): Features low birth rates and low death rates. Population growth is minimal, near zero, or even negative (population decline) if the birth rate falls below the death rate.

These stages reflect changes in a country’s birth and death rates over time as it develops economically, socially, and technologically, impacting public health needs and resource allocation.

Leading Causes of Death

Key Statistics

• An analysis of leading causes of death in young adults, especially college-aged students (typically ages $18-24$), frequently highlights:

  • Unintentional injuries: This category often includes motor vehicle accidents, accidental poisonings (especially drug overdoses), and falls. These are a major concern due to their preventable nature and significant impact on this age group.

  • Cancer: While less common than in older adults, certain cancers can impact young adults. Early detection and lifestyle factors are relevant even in earlier age groups.

  • Heart diseases: Though more prevalent in older populations, some congenital heart conditions or early onset heart issues can affect younger individuals, and lifestyle choices in youth can set the stage for later heart disease.

Objectives for the Session

1. Identify various categories of determinants of health, understanding their broad scope and interconnections.

2. Provide specific examples of determinants of health within each category to illustrate their practical relevance.

3. Consider the complex relationships and implications of various determinants of health on individual and population health outcomes, emphasizing their synergistic effects.

Determinants of Health Categories

Key Categories

Recognizing these categories is crucial for developing comprehensive public health interventions, as health is shaped by a multitude of interacting factors, not just biological predispositions.

1. Biological Factors: Intrinsic characteristics such as age, sex, genetic predispositions, and individual biochemical make-up.

2. Environmental Factors: External influences including the quality of outdoor air, water quality, and exposure to toxic substances in both natural and built environments.

3. Socioeconomic Factors: Societal conditions that affect an individual's resources and opportunities, such as income level, educational attainment, employment status, and social support networks.

4. Behavioral Factors: Individual choices and habits that impact health, including alcohol consumption, tobacco use, dietary patterns, and levels of physical activity.

Biological Determinants Explained

• Age: Different age groups face distinct health risks and disease susceptibilities. For instance, infants are vulnerable to infectious diseases, while older adults are more prone to chronic degenerative conditions.

• Sex: Biological differences between males and females lead to varying health outcomes and prevalence rates for certain diseases (e.g., hormonal influences, genetic predispositions on X and Y chromosomes). Behavioral and social gender roles also contribute to these differences.

• Genetics: Inherited genetic information plays a significant role in an individual's predisposition to certain diseases (e.g., cystic fibrosis, sickle cell anemia, certain cancers) and can influence responses to environmental factors.

• Biochemistry: Variations in an individual's unique biochemical profile, including metabolic rates, hormone levels, and neurotransmitter balance, can affect overall health, disease risk, and treatment efficacy.

Alcohol and Tobacco Usage Statistics

Tobacco Statistics

• Current smoking rates in the U.S. have shown a significant decline, decreasing from $20.9$% in 2005 to $15.1$% in 2015. This reduction is largely attributed to public health campaigns, increased taxation, and smoking bans.

• Despite declines, smoking remains a leading cause of preventable death, causing over $480,000$ deaths annually in the U.S., accounting for approximately $1$ in every $5$ deaths. This includes deaths from cancer, heart disease, stroke, and chronic obstructive pulmonary disease (COPD).

• Gender Comparison: Historically, men have higher rates of tobacco use than women, with current statistics showing men at $16.7$% compared to women at $13.6$%. Public health efforts often target gender-specific cessation strategies.

Alcohol Usage

• In 2023, a substantial majority of individuals ages $18$ and older, $84.9$%, reported having consumed alcohol at some point in their lives, indicating widespread exposure to alcohol.

• Past-month binge drinking rates show a statistically significant difference between males ($28.5$%) and females ($30.5$%) aged $18$ to $25$. Binge drinking, defined as consuming multiple drinks on one occasion, is a significant public health concern due to its association with injuries, violence, and chronic health problems.

Leading Causes of Death by Age Group

• The period of 2021-2022 highlights alarmingly high overdose death rates, particularly among young adults. This trend underscores the opioid crisis and the rise of illicit drug use, leading to premature mortality.

Rate of Drug Overdose Deaths (per 100,000 population)

• $15-24$ years: $20.9$ (in 2021), increasing the focus on prevention and harm reduction for this vulnerable age group who may be experimenting with substances or facing mental health challenges.

• $25-34$ years: $53.1$ (in 2022), indicating a peak in overdose mortality for early to mid-adulthood, often linked to substance dependence and economic stress.

• Subsequent age groups also show significant rates, emphasizing that the overdose crisis impacts a broad spectrum of the population, requiring multi-faceted public health interventions.

Physical Activity Patterns

Prevalence of Physical Inactivity

• From 2017 to 2020, $25.3$% of U.S. adults reported physical inactivity, meaning they engaged in no leisure-time physical activity. This sedentary lifestyle contributes significantly to the burden of chronic diseases such as obesity, heart disease, type 2 diabetes, and certain cancers.

• Trends show varying participation levels by age, socioeconomic status, and community structure, highlighting disparities in access to safe and convenient opportunities for physical activity. Older adults and individuals in lower-income communities often face greater barriers.

Dietary Behaviors

Statistics on Fast Food Consumption

• More than $1/3$ of children and adolescents (ages $2-19$ years) consumed fast food on any given day. This high rate of consumption often means higher intake of calories, unhealthy fats, sodium, and sugars, contributing to increased risks of childhood obesity and related health issues.

Caloric Intake from Fast Food

• Trends in caloric intake from fast food, measured from 2003 through 2018, show increasing health implications. A diet consistently high in fast food contributes to poor nutritional quality, impacting weight management, metabolic health, and increasing the risk of chronic diseases throughout the lifespan.

Socioeconomic Determinants

Key Influences

• Education: Higher levels of education are strongly correlated with better health outcomes, as education often leads to higher income, better jobs, and greater health literacy. It empowers individuals to make informed health decisions.

• Income: Individuals with higher incomes generally have better access to quality healthcare, nutritious food, safer housing, and less stressful living environments, all of which contribute to improved health.

• Employment: Stable and well-paying employment provides financial security, health benefits, and a sense of purpose, while unemployment or precarious work can lead to chronic stress and limited access to resources.

• Housing and Neighborhood conditions: Safe, affordable housing and supportive neighborhoods with access to green spaces, healthy food options, and low crime rates are critical for physical and mental well-being. Poor housing quality (e.g., lead paint, mold) and unsafe neighborhoods negatively impact health outcomes.

Health Status by Education Level in 2018

• A clear correlation exists between education levels and self-reported health status. Individuals with higher educational attainment (e.g., college graduates) consistently report better health compared to those with lower educational levels (e.g., less than high school diploma). This reflects the cumulative advantages associated with education.

Health Status by Poverty Status

• Poverty clearly defines health perception; individuals categorized based on their poverty status often show varied conditions from excellent to poor health. Those living below the poverty line typically report significantly poorer health, higher rates of chronic diseases, and reduced access to healthcare, illustrating the profound impact of economic disadvantage on health and well-being.

Environmental Determinants Framework

Physical and Built Environment Impacts

• This framework identifies how external surroundings critically shape health. Factors include:

  • Climate: Extreme weather events, temperature fluctuations, and air pollution linked to climate change have direct health impacts, including respiratory illnesses, heat-related deaths, and vector-borne diseases.

  • Air quality: Exposure to pollutants from industrial emissions, traffic, and indoor sources can lead to respiratory and cardiovascular diseases, as well as neurological effects.

  • Water quality: Contamination of drinking water sources can cause infectious diseases and exposure to toxic chemicals, highlighting the need for robust water treatment and infrastructure.

  • Waste management: Inadequate waste disposal can lead to environmental pollution, spread of diseases, and exposure to hazardous materials, affecting community health.

  • Infrastructure relevance: Accessible roads, public transport, and functioning sanitation systems are essential for health, facilitating access to healthcare, employment, and reducing exposure to health hazards.

Built Environment Factors

• The design and features of homes, neighborhoods, and urban planning significantly impact health outcomes. This includes:

  • Access to resources: Proximity to healthy food options (e.g., grocery stores vs. food deserts), healthcare facilities, and educational institutions plays a critical role.

  • Recreational space: Availability of parks, sidewalks, and community centers promotes physical activity, social interaction, and mental well-being, while their absence can contribute to sedentary lifestyles and social isolation.

  • Safety and walkability: Safe streets and walkable neighborhoods encourage active transportation and reduce the risk of injuries, fostering healthier communities.

Community Involvement in Health Promotion

Highlights

• Walkable communities improve physical activity likelihood by making it easier and safer for residents to walk, bike, and engage in outdoor recreation. This reduces reliance on cars, lowers pollution, and encourages social interaction, leading to better cardiovascular health and mental well-being.

• Accessibility to recreational facilities (e.g., gyms, sports fields, community centers) contributes significantly to overall well-being by providing structured opportunities for physical activity, promoting social engagement, and offering spaces for stress reduction and leisure. These facilities are particularly important in addressing health disparities by providing resources to underserved populations.

Conclusion of Key Concepts

Determinants Interactions

• The interaction framework vividly illustrates how biological, environmental, socioeconomic, and behavioral determinants do not operate in isolation but rather influence each other in complex, dynamic ways. For example, socioeconomic status can influence access to healthy environments and shape behavioral choices, which in turn affect biological health markers. Understanding these synergistic effects is fundamental for designing holistic and effective public health interventions that target multiple levels of influence, ultimately affecting health outcomes across populations.