Descriptive Epidemiology & Measures Frequency Flashcards
Epidemic:
- Occurrence of disease clearly in excess of normal expectancy
- Community/Period clearly defined
Outbreak
- An epidemic limited to a localized increase in the occurrence of disease
- Sometimes interchanged with ‘cluster’
Endemic
The constant presence of a disease within a given are or population in excess of normal levels in other areas.
Emergency of international Concern
An Epidemic that alerts the world to the need for high vigilance (pre-pandemic Labeling)
Pandemic:
An epidemic spread world wide (global health impact
- Multinational/ Multi-content
The Epidemic Curve
What is it?
- A graphical, time-based depiction generated during an outbreak/ epidemic reflecting the # of cases; by date
what does an epidemic curve visually depict
- MAGNITUDE and TIMING of disease occurrence
Pattern shape of disease occurrence
- Common Source: disease is derived from a single point of source
- Propagated Source: whereby disease is spread person to person
How can the epidemic curve help
Helps to form hypotheses regarding epidemic: routes of transmission
Probable exposure, and incubation period.
Objectives in Epidemiology
- Identify Patterns
- Determine extent disease
- Study natural course of disease
- Identify the cause of state or event as well as risk factors
- Evaluate effectiveness of measures
- Assist in developing public heath policy
Assumption made in Epi
The disease is not random
Systematic investigations find causal factors
3 W’s of descriptive Epidemiology
who what when
1 W of analytic epidemiology
why (association vs causation)
6 core functions of EPI
- Public Health surveillance
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3 types of relative measures of disease
Proportions (part over whole)
Ratios
Rates
3 key factors in comparing measures of disease frequency between groups
- # of people affected.
- Size of the population
- Time the population is followed.
