Flashcards in Epidemiology - Key Concepts Deck (24):
The study of the distribution and determinants of health-related states or events in specified population and the application of this study to control of health problems
What are the three components of the epidemiological triad?
List some factors that are included under the heading of 'Time".
Epidemic (temporary increase)
List some factors that are included under the heading of 'Place'.
List some intrinsic & extrinsic factors that are included under the heading of 'Person'.
- marital status
- ethnic group
List the 7 stages of the continuum of health.
What are the 4 elements of the epidemiologists bathtub?
The rate at which new cases occur in a population during a specific period
The number of existing cases in a population at a point in time
What can affect the prevalence?
Recovery & death
How is the incidence rate calculated?
Number of new people with outcome over a time period (either recovery or death) x100000
Total number of people in the group at risk during that time period
How is the prevalence rate calculated?
Number of people with outcome at a point in time x100
Total number of people in the group
What is the difference between point prevalence and period prevalence?
Point prevalence: at one point in time
Period prevalence: over a time period
Study designs can be categorised. List the studies that fall under the heading, 'Observational'.
Study designs can be categorised. List the studies that fall under the heading, 'Experimental'.
RCT (randomised controlled trial)
What is meant by ecological fallacy?
Individual variation in a population
How is an ecological study similar to a case-series?
The only difference is that a case-series is individually focused, whereas an ecological study is focused on a population; unit of study is a population as opposed to an individual
Give a good example of an ecological study.
John Snow and his discovery of the outbreak of cholera source in London - Broad Street Pump
Briefly summarise what a case control study is.
Cases have the disease/condition
Controls don't have the disease/problem
These are the OUTCOMES
Therefore, you need to look BACKWARDS in order to ascertain what proportion of cases and controls had undergone EXPOSURE
How is a cohort study similar to a case control study?
A cohort study is also retrospective - look backwards to explore exposure
Explain how a cohort study is conducted.
Gather a population free of disease
Expose one group to the disease, leave the other group unexposed
Assess outcome of each group - where is greatest incidence of disease
What is a case series?
A series of cases with the same disease (often consecutive)
List the 3 steps of conducting a cross-sectional study
1. Sample a population
2. Estimate the proportion - different exposures, signs, symptoms & outcomes
3. Use data for reinforcement and to describe prevalence/explore associations