PHS 2101 - Chapter 1

• what is public health?

  • Science and art of preventing disease, prolonging life and promoting health and efficiency through organized community effort.
  • Application of scientific and technical knowledge to prevent disease and promote health
  • Set of organized community efforts that fulfill society’s interest in assuring conditions in which people can be healthy
• who is the community?

  • Public health is both local and global
  • Who “organizes” for the public good?
  • Who has power to legislate?
  • Role of government
• examples of public health efforts

  • Provision of clean water, sanitation
  • Immunization programs
  • Restrictions on smoking in public places
  • Access to medicine and medical care
  • Assuring safety of drugs and food
  • Surveillance of disease
  • Response to disasters and epidemics
  • Reducing poverty
  • Food security and nutrition
  • Literacy and education
• goals of public health

  • Monitor health of population
  • Improve health status of the population
  • Respect for perspectives, values and needs of diverse members of community served
• specific responsibilities of the public health system

  • Prevent epidemics and spread of disease
  • Protect against environmental hazards
  • Prevent injuries
  • Promote healthy behaviors
  • Assure quality and accessibility of health services
  • Respond to disasters
  • Assist communities in recovery
• who is responsible for public health?

  • Public, private and voluntary organizations
  • Government agencies
  • Academia
  • Health care providers
  • Hospitals and clinics
  • Community-based organizations
  • Businesses
  • Advocacy groups, e.g. NGOs
  • Professional associations
  • Media
  • Individuals
• role of government agencies

  • Assure that all vital system elements are in place
  • Coordinate core functions and essential services
  • Ensure that the mission to improve health of the community is addressed adequately
  • Why government?
  • Regulatory powers of the state
• public health vs medical care

  • Medical care alone does not constitute public health
  • Medical care is part of public health
  • Focus of each is different
• Medical Care

  • Individual
  • Technology
  • Treatment
• Public Health

  • Population
  • Provision for basic needs
  • Equity
  • Prevention
• Public Health Versus Medical Care

  • In medicine, the patient is the individual; in public health, the patient is the community.
  • Public health diagnoses the health of the community using public health sciences.
  • Treatment of a community involves new policies and interventions.
  • Goal of medicine is to cure; goal of public health is to prevent disease and disability.
  • Less than 3% of the nation’s total health spending is devoted to public health.
  • Life expectancy of Americans has increased by 30 years over the 20th century, and only 5 of the 30 years are attributed to modern medicine.
• Medical Care vs. Public Health Funding in U.S.

  Strong emphasis on medical technology, less on prevention
• PREVENTION: Hallmark of Public Health

  • Environmental improvements
  • Control of infectious diseases
  • Vaccines
  • Improved occupational & product safety
  • Early diagnosis of disease
  • Identification of risk factors for chronic diseases: smoking, diet
  • Management of chronic diseases***
• Public Health: Science and Politics

  • Science is how we understand threats to health, determine what interventions might work, and evaluate whether the interventions worked.
  • Politics is how we as a society make decisions about what policies to implement.
  • Politics is part of both the policy development and assurance functions of public health.
  • Community pays for public health initiatives through taxes.
• Public Health Science Disciplines

  • Epidemiology
  • Statistics
  • Biomedical Sciences
  • Environmental Health Science
  • Social and Behavioral Sciences
  • Health Policy and Management
• Epidemiology

  • Epidemiology is the basic science of public health.
  • The study of epidemics
  • – Focuses on human populations, usually starting with an outbreak of disease in a community
  • – Looks for common exposures, seeking the causative factor
  • Deciphers causes of new disease and prevents spread of old, well-understood diseases
  • Epidemiologists are mainstays of local public health departments.
  • – “Shoe-leather epidemiology”
• Statistics

  • Governments collect health data on the population.
  • These numbers are diagnostic tools for the health of the community.
  • The science of statistics is used to calculate risks and benefits.
  • Statistical analysis is an integral part of any epidemiological study seeking the cause of a disease.
  • Statistical analysis is an integral part of any clinical study testing the effectiveness of a new drug.
• Biomedical Sciences

  • A major portion of human disease is caused by microorganisms.
  • Control of infectious diseases was a major public health focus in the 19th and early 20th centuries.
  • Biomedical research remains important to understanding and control of new diseases and noninfectious diseases.
  • – Chronic diseases
  • – Genetics
• Environmental Health Science

  • A classic component of public health:
  • – Much of the public health improvement in the U.S. in the 20th century was due to improved environmental health.
  • Health is affected by exposure to environmental factors:
  • – Air quality
  • – Water quality
  • – Solid and hazardous wastes
  • – Safe food and drugs
  • – Global environmental change
  • Thousands of new chemicals enter the environment every year, and little is known about their effect on human health.
• Social and Behavioral Sciences

  • Behavior is now the leading concern of factors that affect people’s health.
  • A theory of health behavior is that social environment affects people’s behavior.
  • – Major health threats are tobacco, poor diet, and physical inactivity and injuries.
  • – Blacks have a lower overall life expectancy than whites even when incomes are similar.
  • – Other ethnic minority groups are also at increased risk for a variety of health problems.
• Health Policy and Management or Health Administration

  • This area of study examines the role of medical care in public health.
  • Cost of medical care in the U.S. is out of control.
  • U.S. has a high percentage of population without health insurance.
  • – These people often lack access to medical care.
  • Quality of medical care can be measured and is often questionable.
  • Medical care has eaten up profits that could be used more beneficially for education, housing, and the environment.
• Public Health: Prevention and Intervention

  • Primary prevention prevents an illness or injury from occurring at all.
  • Secondary prevention minimizes the severity of the disease or injury once it has occurred.
  • Tertiary prevention minimizes disability by providing medical care and rehabilitation services.
• Public Health Approach

  • Define the health problem.
  • Identify risk factors associated with the problem.
  • Develop and test community-level interventions to control or prevent the cause of the problem.
  • Implement interventions to improve the health of the population.
  • Monitor interventions to assess their effectiveness.
• Chain of Causation: Where and What do you Target?

  • Chain of Causation involves identification of:
  • – Agent (ex. Pathogenic bacteria)
  • – Host (ex. human)
  • – Environment (ex. means of transmission)
  • This is a traditional approach to dealing with infectious diseases.
  • Interventions can focus on any of these targets.
  • This model can also be used for other kinds of illnesses or injuries.
• Core Functions of Public Health

  • Assessment
  • Policy development
  • Assurance
• Assessment

  • “Diagnosis”
  • Collection of data
  • Evaluation of data
  • Epidemiological studies
  • Analysis and assembly of health information
  • Basis for recommending strategy to address health event or issue
• Policy Development

  • “Treatment plan”
  • Involves utilization of scientific knowledge in devising strategic plan
  • Determination of available resources and appropriate allocation of resources
  • May involve political debate, devising regulations or passing legislation: community commitment to action
• Assurance

  • Action taken to provide “treatment”
  • Provision of services to meet community need
  • Enforcement of laws and regulations
  • Education
  • Basic medical services
  • Environmental remediation