1. epidemiology

2. epidemiology Epidemiology (epi/dem/o/logy) comes from
Epi: meaning “on or upon”
Demos: meaning “people”
Ology: meaning “the study of”
Epidemiology is the study of the distribution and determination of the causes of health-related conditions or events in populations. It is used in healthcare and especially with infectious disease.
epidemiology

3. How epidemiology is used

4. community health assessment
These questions are researched when doing a community assessment:
What are the actual and potential health problems in the community?
Where do they occur?
Who is at risk?
Which problems are declining over time?
Which ones are increasing or have the potential to increase?
How do these patterns relate to the level and distribution of services available?
community health assessment

5. The Epidemiologic Approach
Case Definition
A set of standard criteria for deciding whether a person has a particular disease or other health- related condition
The Epidemiologic Approach

6. Statistics and Reports
When physicians diagnose a case of a reportable disease they send a report of the case to their local health department.
Time - when the case occurred
Place - where the patient lived
Person - the age, race, and sex of the patient
Statistics and Reports

7. Statistics and Reports
Health departments convert the case counts into rates, which relate the number of cases to the size of the population where they occurred
Statistics and Reports

8. Types of Epidemiology

9. Descriptive Epidemiology
Organize and summarize data according to time, place, and person
Time – disease rates change over time
Example: the seasonal increase in influenza with the onset of cold weather
Time data is usually shown on a graph
Descriptive Epidemiology

10. Descriptive Epidemiology
Place - describe a health event by place to gain insight into the geographical extent of the problem and similarities in location.
Residence
Birthplace
Place of employment
School district
Hospital unit
Descriptive Epidemiology

11. Descriptive Epidemiology
Person:
inherent characteristics of people
Age
Race
Sex
Acquired Characteristics
Immunity
Marital status
Descriptive Epidemiology

12. Descriptive Epidemiology
Activities
Occupation
Leisure activities
Use of medications/tobacco/drugs
Descriptive Epidemiology

13. Descriptive Epidemiology
Conditions in which people live
Socioeconomic status
Access to medical care
Descriptive Epidemiology

14. Analytic Epidemiology
Used to search for causes and effects, or the why and the how.
Looks for relationships in the data
Analytic Epidemiology

15. Causation

16. Cause of disease is a factor (characteristic, behavior, event, etc
Cause of disease is a factor (characteristic, behavior, event, etc.) that influences the occurrence of disease.
An increase in the factors leads to an increase in disease.
Reduction of the factors leads to a reduction in disease
Causation

17. Epidemiologic triangle
Traditional model of infectious disease causation.

18. Epidemiologist use the Chain of infection

19. Epidemiology: Level of Disease
Level of Disease - amount of a particular disease that is usually present in a community
Increasing amount of disease
Sporadic
Endemic
Epidemic
Pandemic
Epidemiology: Level of Disease

20. Epidemiology: Level of Disease
Sporadic - irregular pattern of occurrence, with occasional cases occurring at irregular intervals
Endemic - persistent level of occurrence with a low to moderate disease level
Epidemic or Outbreak- occurrence of a disease within an area is clearly in excess of the expected level for a given time period
Example: Ebola epidemic or outbreak of 2014
Pandemic - an epidemic spreads over several countries or continents, affecting a large number of people
Example: Bubonic plague and AIDS
Epidemiology: Level of Disease