1.1. Population Data - Epidemiology, Incidence, Prevalence, and Risk Flashcards
What does the study of “Epidemiology” look at?
It looks at the nature and type of illness in society (using the numerical science of epidemiology) by looking at the time, place and person affected
E.g. rate of occurrence of heart disease between 18th century English Women and 20th century Finish Men
What is the most recent example of an Epidemiological Study
Cholera Epidemic in Haiti, 2011
What are the 3 main aims of Epidemiology?
- Description
- Explanation
- Disease Control
What does the “Description” aspect of Epidemiology entail?
Describing the amount and distribution of disease in human populations
- What does the “Explanation” aspect of Epidemiology entail?
- How does this happen?
- To elucidate the natural history, and identify aetiological factors for the disease
- By combining Epidemiological data with data from other disciplines
What does the “Disease Control” aspect of Epidemiology entail?
Providing the basis on which preventative measures, public health practices, and therapeutic measures can be developed, implemented, monitored and evaluated
What is compared in Epidemiology?
Study Populations
What may define the “Study Population”, being compared in Epidemiology?
- Age
- Sex
- Location
- (The same group over) Time
In comparing “Study Populations”, what is this used to detect?
- Aetiological clues (what causes the problem)
- The scope for prevention
- The identification of high risk or priority groups in society
- What does “Clinical Medicine” deal with?
2. What does “Epidemiology” deal with?
- The individual patient
- Populations
Note - it is essential to be clear about which populations are being talked about when studies / surveys / formulation of hypotheses are being carried out
What is used to be clear about the risk to a population?
Ratios (expressed in terms of a specified time period, and national “at risk” population)
- What is the ratio used to express risk in a population?
2. Use an example of Deaths from IHD in men aged 55-64 in Grampian in 1990:
- Number of Events / Population at Risk
2: Deaths from IHS in men aged 55-64 in Grampian in 1990 /
All men aged 55-64 in Grampian in 1990
What are the ratios, used to express risk in a population, often converted into?
- Rates, by expressing them in terms of a specified time period (e.g. per year)
- A notional “at risk” population in “X per 1000; per 10000…”
What is the significance of the “at risk” part of the ratio, used to express risk in a population?
- Everyone in the denominator (total populous studied) must have the possibility of entering the numerator (those with the condition)
- All those people in the numerator (those with the condition) have come from the denominator (total populous studies)
What is the definition of “Incidence”?
The number of new cases of a disease in a population in a specified period of time