Week 141 - Measurements in populations II Flashcards Preview

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Flashcards in Week 141 - Measurements in populations II Deck (7):
1

What is chance?

The occurrence of an event based on probability

2

What is selection bias?

The selection of controls that are not representative of the population

3

What is information bias?

Recall bias
i.e. asking a person what they ate at a certain event
- people will recall information to a different accuracy

4

What is a confounding variable?

A variable that can cause or be associated with the disease and is also linked the the exposure of interest

i.e. a study between alcohol intake and IHD
- those who drink alcohol are more likely to smoke, and smoking has an association with IHD

5

What is residual confounding and how can this be dealth with?

When all confounding factors have been accounted for but there remain unknown confounders

Can be dealth with by randomisation

6

What is standardisation ad what types are there?

A technique used to remove the effects of differences in confounders (i.e. age) when comparing two or more populations

Two types:
- Indirect
- Direct

7

What is indirect standardisation?

Rate of a certain disease in a reference population is calculated then these raes are applied to the study population

If calculated rates < actual study rates => study population has a higher rate of disease