Epidemiology

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Epidemiology

• Nature, cause, control and determinants of the
  frequency and distribution of disease, disability
  and death in human populations

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What is it?

• A science, using the traditional concepts of the
  scientific method
• A method, using the concepts from several fields

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Purposes

• 1. Explain the etiology
• 2. Is the data consistent with what we know?
• 3. Develop prevention and control measures

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The Epidemiologist

• Public health scientist, MPH degree
• May be a physician
• Uses statistical, medical, scientific, computer,
  and behavioral materials and tools
• Every county has an epidemiologist
• Federal government (USPHS)
• Community hospitals

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Three Considerations

• Time
• Place
• Person

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Epidemics

• Endemic-the usual level, expected
• Hyperendemic- above the normal level, contained
  in a group or location
• Holoendemic - Normally found in a group, example
  chickenpox
• Epidemic - new cases exceed the prevalence
• Pandemic - Widespread (AIDS)

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Incidence Prevalence

• Incidence - how many people get the disease over
  time?
• Prevalence - the number of people who have the
  disease at a given point

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Examples

• Two students at UCF are diagnosed with measles
• Nosocomial infections post op in an orthopedic
  unit
• Food poison in school lunches
• Breast cancer in a specific group of women
• Diseases associated with tobacco products
• Physician practice patterns
• Quality of an HMO

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More Examples...

• Does our hospital, HMO, nursing home, etc. have
  better quality of care than others?
• Infectious diseases, where are they? when will
  they strike next?

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Disease Transmission

• Fomites - inanimate objects
• Vectors - insects or small animals
• Reservoirs - living or inanimate objects where
  organisms live and grow
• Zoonoses - animal transmits to people
• Carrier - contains, carries spreads infectious
  diseases

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Case Concept

• Primary case - introduces the disease
• Index case - first found case
• Secondary case - become infected by the primary
  case
• Case fatality ratio - deaths per 100 episodes
• Case severity - ALOS is an example

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Levels of Healthcare

• Primary - basic physician healthcare services
• Secondary - basic hospital services (having a
  baby, repair a hernia, fix a broken arm)
• Tertiary - ICU, heart and brain surgery

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Prevention

• Primary - health promotion, education, health
  protection
• Secondary - screening and detection (blood
  pressure checks at health fairs)
• Tertiary - retard or block further progression

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Managerial Epidemiology

• Use the methods and databases of the
  epidemiologist
• Apply appropriate outcome measures to your
  strategic plan
• Market research database
• Improved quality and reduced cost