Introduction to public health
High-yield summary — Introduction to Public Health
Based on your lecture: :codex-file-citation{path=“sandbox:/workspace/scratch/499bd51909f0/upload/INTRODUCTION_to_PUBLIC_HEALTH.pdf” purpose=“source”}
1. Definition and mission
Public health is the science and art of preventing disease, prolonging life, and promoting health through organized efforts of society.
Remember the 3 Ps: Prevent → Prolong → Promote.
Its mission is to create conditions in which people can be healthy, benefit the largest number of people, and reduce health inequalities.
Public health | Clinical medicine |
Focuses on populations, including healthy people | Focuses on individual patients |
Emphasizes prevention and health promotion | Emphasizes diagnosis and treatment |
Uses epidemiology to identify community problems | Uses history, examination, and investigations |
Acts through policies, education, and health services | Acts through medical and surgical treatment |
Operates wherever people live and work | Commonly operates in clinical settings |
2. Three core functions — VERY HIGH YIELD
Core function | Meaning | Related essential services |
Assessment | Collect and analyze information about population health | Monitor health; diagnose and investigate |
Policy development | Use scientific evidence to guide decisions | Inform, educate, empower; mobilize partnerships; develop policies |
Assurance | Ensure needed services are available and effective | Enforce laws; link people to care; ensure workforce competence; evaluate services |
Research supports all three functions.
Exam trap: Authority is not a core function.
3. The public health approach
Memorize the order and the question answered:
Step | Main question |
1. Surveillance | What is the problem? |
2. Risk factor identification | What is the cause? |
3. Intervention evaluation | What works? |
4. Implementation | How do we do it? |
Epidemiology: Study of the distribution and determinants of health-related states/events in populations, and application of this knowledge to control health problems.
Distribution: Who? Where? When?
Determinants: Why? How?
Public health surveillance: Ongoing, systematic collection, analysis, and interpretation of health data to guide planning, implementation, and evaluation.
Distinction: Surveillance tracks the problem; epidemiology investigates its patterns and causes.
4. Ten essential public health services
Monitor health.
Diagnose and investigate health problems.
Inform, educate, and empower people.
Mobilize community partnerships.
Develop policies.
Enforce laws.
Link people to/provide care.
Assure a competent workforce.
Evaluate services.
Research new solutions.
5. Four determinants of health
Determinant | Examples |
Genes and biology | Heredity, age, biological characteristics |
Health behaviors | Smoking, diet, physical activity |
Social/societal characteristics | Poverty, education, housing, employment, social support |
Health services/medical care | Access, availability, and quality of care |
The lecture also emphasizes environmental conditions, such as water, sanitation, and living and working conditions.
Key idea: Population health depends on much more than medical care.
Health outcome: A result affecting the length or quality of life.
6. Health impact pyramid — VERY HIGH YIELD
Memorize from bottom to top, using the lecture’s wording:
Level | Intervention |
Bottom | Socioeconomic factors |
↑ | Making healthy decisions the default |
↑ | Preventive medicine |
↑ | Medical care |
Top | Counseling and education |
Moving down → greater population health impact.
Moving up → more individual effort required.
Why? Improving social conditions and environments reaches many people without requiring each person to repeatedly change their behavior.
7. Three domains of public health
Domain | Main focus | Examples |
Health protection | Protect people from health threats | Communicable diseases, chemicals, radiation, environmental hazards, emergency response |
Health improvement | Improve determinants and behaviors | Education, housing, employment, poverty reduction, healthier lifestyles |
Improving services | Improve quality, effectiveness, and access | Evidence-based planning, cost-effective treatment, audit, evaluation, equity |
Do not confuse: These domains differ from the three core functions: assessment, policy development, assurance.
8. John Snow and cholera
John Snow: Father of modern epidemiology.
Investigated the 1854 London cholera outbreak.
Linked cholera to sewage-contaminated water, challenging the “bad air” explanation.
Demonstrated how investigating an outbreak can guide action to stop exposure.
Exam association: John Snow → cholera → contaminated water → epidemiology.
9. Partners and their roles
Partner | Main role |
Media | Public discussion, health communication and education |
Employers/businesses | Workplace wellness, benefits, healthy working conditions |
Government | Policies, planning, education; health in all policies |
Academia | Education, training, research, public service |
Health care sector | Individual care and collaboration with public health |
Health in all policies: Consider health effects in decisions across sectors, including housing, transport, and education.
10. Historical milestones and achievements
Dates worth remembering:
1848: Public Health Act in the United Kingdom.
1854: John Snow’s cholera investigation.
1955: Polio vaccine introduced.
1970: US Environmental Protection Agency established.
1988: Global polio eradication initiative launched.
Major achievements include vaccination, infection control, maternal and child health, cardiovascular prevention, tobacco control, safe water and sanitation, food safety, cancer prevention, injury prevention, and pandemic preparedness.
11. Principles emphasized in the lecture
Population approach: Improve health across communities.
Life-course approach: Early experiences and cumulative exposures affect health throughout life.
Multisectoral approach: Health requires collaboration across disciplines and sectors.
Equity and social justice: Reduce inequalities and improve access.
Ethics: Beneficence, non-maleficence, justice, solidarity, accountability, transparency, and participation.
Rapid exam recall
3 Ps: Prevent disease, prolong life, promote health.
3 core functions: Assessment, policy development, assurance.
Monitor + investigate: Assessment.
Ensure access to care: Assurance.
Approach: Problem → cause → what works → implementation.
4 determinants: Biology, behavior, society, services.
Pyramid down: Greater impact.
Pyramid up: Greater individual effort.
3 domains: Protection, improvement, improving services.
John Snow: Cholera, London, 1854, contaminated water.