HCD Public Health - Comprehensive Public Health Notes for Exam Preparation
Public Health: Definitions and Core Concepts
Public health is the science and art of preventing disease, prolonging life, and promoting health through the organized efforts of society, organizations, public and private communities, and individuals.
Source definition from C. A. Winslow (over 100 years old):
Public health is the science and art of preventing disease, prolonging life, and promoting health through organized efforts of society, organizations, public and private communities, and individuals.
Key takeaways: public health combines scientific study (science) with acting in the world (art) to effect population health, not just understand it.
Public health also emphasizes prevention as its core focus, distinguishing it from many other fields that focus on treatment after illness or injury.
The Institute of Medicine adds that the mission of public health is the fulfillment of society's interest in assuring the conditions in which people can be healthy, by organizing community efforts to aid prevention and the promotion of health.
Public health vs medicine (important distinctions):
Public health focuses on populations (groups, communities), not just individuals.
Public health prioritizes prevention; medicine emphasizes treatment and clinical care.
Public health is not solely governmental; it encompasses academia, non-profits, and community organizations, all contributing to population health.
The Goals and Scope of Public Health
Primary goals: disease prevention and health promotion.
Prevention includes reducing risk factors and stopping health problems before they occur (e.g., immunizations, safety measures).
Health promotion involves enabling people to live healthier lives, not just reducing disease.
Public health interventions target populations or communities, not just single patients.
The Three Core Public Health Functions (and the 10 Essential Public Health Services)
Core framework (often depicted around a circle):
Assessment: understand the health problems, their distribution, and determinants at a population level.
Policy Development: create and implement strategies to address health problems (policies, regulations, programs).
Assurance: ensure that essential health services are available, and public health infrastructure functions (governance, workforce, surveillance, etc.).
These core functions map onto the broader set of essential public health services (monitor health status, diagnose and investigate, inform/educate/empower, mobilize community partnerships, develop policies, enforce laws, link to care, assure a competent workforce, evaluate, research). The speaker emphasizes the three core functions with concrete examples.
Example context: Occupational safety policy (OSHA), the general duty clause, and enforcement mechanisms.
Public health infrastructure includes federal (e.g., Centers for Disease Control and Prevention), state health departments, and local health departments (e.g., Boston Public Health Commission).
Public Health Approach and the ICD Framework
The public health approach typically involves:
1) Defining the problem (problem definition, using standard case definitions and classifications like ICD codes).
2) Describing the affected population (who, where, when) and identifying risk factors (assessment/epidemiology).
3) Developing strategies to address the problem (policy, programs, interventions).
4) Implementing and applying interventions in practice.
5) Evaluating the effectiveness of interventions (evaluation) to see if outcomes improve (e.g., fewer fatalities, reduced incidence).ICD: International Classification of Diseases, used to define and classify diseases and injuries for case identification and surveillance.
Descriptive epidemiology (part of assessment):
Characterizes the distribution of disease in the population by time, place, and person (the who, where, and when).
Key questions include: Who is affected? Where? When does it occur? What are the demographic characteristics?
Identifies risk factors and potential etiologies to guide prevention.
Causation in epidemiology: identifying the causes of health problems to inform prevention efforts (e.g., identifying infectious agents and transmission pathways).
Classic illustrative example: John Snow and the cholera outbreak in London (mid-1800s).
He mapped cholera cases and linked them to a water pump on Barratt Street, showing spatial clustering around the pump source.
He calculated mortality rates by district served by different water pumps, finding higher rates where water came from a contaminated source.
Intervention: removing the pump handle (engineering/public health intervention) to stop transmission, illustrating an intervention beyond education or policy alone.
Prevention: Primary, Secondary, and Tertiary
Primary prevention: prevent illness or injury from occurring in the first place.
Examples: immunization/vaccination, tobacco cessation programs, nutrition enhancement, environmental interventions, improving living/working conditions.
For infectious diseases, primary prevention often means preventing transmission (e.g., vaccines, reducing exposure).
For non-communicable diseases (NCDs), primary prevention involves reducing risk factors (e.g., smoking cessation to prevent lung cancer).
Secondary prevention: minimize severity or progression once a disease or injury has occurred; early detection and intervention.
Examples: cancer screening (colorectal, breast, cervical), blood pressure screening to detect hypertension early.
Emphasizes identifying disease in asymptomatic or early stages to allow reversal or better management.
Tertiary prevention: minimize symptoms and improve function after a disease is established and potentially non-reversible.
Examples: physical therapy, cardiac rehabilitation, diabetic care, rehabilitation programs.
Important nuance: even though secondary and tertiary prevention occur after disease onset, they are still considered public health strategies when applied at the population level (e.g., screening programs integrated into public health systems).
Fields within Public Health
Epidemiology
The study of the distribution and determinants of health outcomes in populations.
Descriptive epidemiology: distribution by person, place, time.
Etiology: identifying causes; designing prevention strategies.
Often described as the diagnostic discipline of public health.
Biostatistics
Applies statistical methods to study health phenomena and evaluate interventions.
Key tools include prevalence and incidence calculations, relative risks, odds ratios, and study designs.
Social and Behavioral Health Sciences
Focuses on how social determinants and individual behaviors shape health outcomes.
Social determinants of health include economic factors, education, housing, neighborhood context, transportation, access to healthcare, food security, and social support.
Behavioral determinants include smoking, diet, alcohol use, physical activity, and how these behaviors interact with environment and policies.
Environmental Health
Studies how environmental factors (pollution, climate, radiation, built environment) affect health.
Includes topics like air pollution, occupational exposures, climate change, and food/drug regulation as environmental determinants.
Health Policy and Management
Examines health systems, policies, and the management of healthcare resources.
Key discussion: rising healthcare costs, drivers like technology, aging populations, administrative costs, access to care, and policy interventions such as the Affordable Care Act (ACA).
The interconnections among these fields illustrate how population health is influenced by biology, behavior, environment, and policy.
Social Determinants of Health (SDH)
Education (educational attainment) and its impact on health outcomes and access to opportunities.
Education shapes jobs, income, insurance, and psychosocial well-being; it also affects knowledge about health behaviors.
Educational attainment is socially determined via public investment in education, access to loans, and public schooling systems.
Economic factors: income level, job stability, and socioeconomic status influence health outcomes and access to resources.
Neighborhood and housing conditions: quality of housing, neighborhood safety, availability of green spaces, and access to physical activity resources.
Transportation and access: availability of reliable transportation affects access to healthcare, healthy foods, and opportunities for physical activity.
Healthcare system access: quality and availability of health services, including medications and preventive care.
The SDH framework emphasizes that health disparities arise from social and structural factors as well as individual choices.
Behavioral Determinants of Health
Individual health behaviors and choices (and how environments influence those choices):
Smoking (cigarette use) as a major determinant of lung disease and cancer.
Diet quality and composition, caloric intake, and nutritional status.
Alcohol use and other substances.
Physical activity levels and access to safe spaces for activity.
Interplay with environment: access to green spaces can improve activity levels; policies and environment shape behavior.
Public health success example: dramatic decline in smoking in the U.S. since the 1960s, driven by Surgeon General’s reports, advertising bans, litigation, and taxation.
Environmental Health and Climate Change
Environmental determinants include:
Pollution (air, water, soil) and its health impacts.
Built environment: safety of roads, housing quality, and workplace safety.
Radiation and other environmental exposures.
Climate change and its health effects (air quality, heat exposure, vector ecology).
Air pollution studies suggest substantial global mortality; major sources include vehicle emissions and industrial processes; natural events like wildfires (e.g., wildfire smoke from Canada affecting air quality in nearby regions).
Public health response involves both studying exposures and implementing controls to reduce them (regulation, technology, policy).
Health Policy, Management, and Costs
Health policy and management study how health systems operate, how costs rise, and how policies affect access and outcomes.
Cost drivers include: technology and new drugs, administrative costs, aging populations with chronic diseases, and broader access (e.g., ACA) increasing overall spending but improving access.
The Affordable Care Act (ACA) expanded access to care, reducing the number of uninsured but not eliminating costs or disparities entirely.
Trade-offs: improving access can increase total costs unless cost per person is reduced; system-level reforms aim to balance access, quality, and expenditure.
Public Health and Pharmacy Practice: Connections in Practice
Pharmacist role in public health
Access to medications is a key determinant of health and a central public health concern.
Pharmacy access can occur via community pharmacies and within community health centers (which may include pharmacists as part of a broader healthcare team).
Vaccination distribution: pharmacies serve as convenient sites for immunization, alongside clinics and hospitals.
FDA regulation of drugs: FDA regulates drugs and approves new medications; pharmacovigilance and post-marketing surveillance use public health methods to assess efficacy and safety at the population level.
Post-approval drug safety monitoring (phase 4) relies on public health surveillance to identify adverse events.
Public health surveillance methods are used to monitor drug safety and effectiveness in real-world settings.
Prescription Monitoring Programs (PDMPs)
Implemented in many states (e.g., Massachusetts) to track controlled substance prescribing patterns and detect misuse or diversion.
PDMPs help identify patients receiving multiple prescriptions from different providers and facilitate interventions to reduce misuse.
Opioid epidemic and substance use disorders
Overdose mortality rose sharply in the 2010s and remains a major cause of death; fentanyl (a synthetic opioid) is a leading contributor.
Overdoses involve both prescription opioids and illicit substances; stimulant overdoses (e.g., cocaine, methamphetamine) have risen and may be tied to polysubstance use.
Workplace injuries and occupational factors have been linked to opioid misuse and overdoses; construction, farming, fishing, and forestry workers show elevated rates in some settings.
Health care workers face occupational hazards and violence; OSHA’s general duty clause underscores the right to a safe workplace.
The pharmacy world also intersects with public health through pharmacoepidemiology (the study of drug effects in populations) and through education, prevention, and policy initiatives.
Case Illustrations and Historical Contexts
Cholera and John Snow (19th century): a landmark public health epidemiology example showing causal inference and intervention.
Snow mapped cases and identified transmission via a contaminated water source; he used statistics to demonstrate elevated risk around a specific pump.
Intervention (pump handle removal) demonstrated an engineering/public health solution alongside education and policy measures.
Public health milestones and key terms to remember:
ICD: International Classification of Diseases, used to define diseases and standardize case definitions.
Primary prevention examples: vaccination, tobacco control, nutrition programs.
Secondary prevention examples: cancer screenings (colorectal, breast, cervical), blood pressure screening.
Tertiary prevention examples: rehabilitation, chronic disease management programs.
The three core public health functions (assessment, policy development, assurance) guide how prevention and protection are organized at multiple governance levels.
Public Health Minor and Educational Pathways
Public health minor available for students (including pharmacy students) with structured requirements:
Three required courses: biostatistics, introductory public health, and another core course.
At least two electives; many offerings are available, including special topics courses.
The minor provides a pathway to integrate public health perspectives with professional training (e.g., pharmacy).
Invitation to engage: students are encouraged to pursue public health coursework and consider this interdisciplinary approach in their future careers.
Practical Takeaways for Pharmacy Students
Public health principles inform pharmacy practice in several ways:
Medication access and affordability to improve population health.
Vaccination policy and distribution through pharmacies increasing preventive care reach.
Pharmacovigilance and drug safety monitoring using population-level data to inform risk-benefit assessments.
Regulatory science: understanding FDA processes for drug approvals and post-market surveillance.
PDMPs as a public health tool to prevent misuse and overdose.
Opioid crisis and polysubstance use context, with a focus on workplace health and safety and the well-being of healthcare workers.
The public health lens emphasizes collaboration across disciplines (pharmacy, epidemiology, biostatistics, policy, and community organizations) to improve health outcomes.
Final Thoughts and Resources
If you’re interested in public health, consider talking to the presenter about opportunities, including the pharmacoepidemiology track and certificates that complement a PharmD program.
The speaker highlights ongoing work at the Massachusetts Department of Public Health and within public health research that intersects with pharmacy practice.
Contact information and office location provided for follow-up discussions and potential mentorship.
Glossary of Key Terms (quick reference)
Public health: science and art of preventing disease and promoting health at the population level through organized actions.
Prevention: actions to stop health problems before they occur (primary), detect early (secondary), or minimize consequences after onset (tertiary).
ICD: International Classification of Diseases; standard diagnostic tool for epidemiology and public health surveillance.
Epidemiology: study of how diseases affect populations, including distribution and determinants.
Biostatistics: application of statistics to biological/health data to inform decisions.
Social determinants of health: economic, educational, environmental, social, and healthcare access factors that shape health outcomes.
Environmental health: study of environmental factors that affect health, including pollution and climate change.
PDMP: Prescription Drug Monitoring Program; system to track controlled substance prescriptions.
Pharmacoepidemiology: study of the uses and effects of drugs in large populations; relevant to drug safety and effectiveness.