Revision session notes

Question 1

Rate ratio vs odds ratio

Answer 1

rate ratio - occurs within the population

it is the incidence rate / per person time

odds ratio - does not include time as a measure
will not account for 1 person with 3 separate events

odds adjusts for confounders

we can do a ratio of odds by dividing two odds together

Question 2

the 4 studies

you will be asked to read a study and determine what type it is

Answer 2

ecological study - 1 group of people - population level exposure - no control of exposure level

X-sectional study - 1 group of people - individual level exposure - no control of exposure level

Cohort study - 2 group of people (exposed and not exposed) - select on level of exposure - we control exposure level

Case control - 2 group of people (sick and well) - case vs non case selection -we control exposure level

Question 3

bias vs confounding

Answer 3

bias - is a selection issue - people outside maccies are fat, so dont ask people only there

confounding - factors that are not in study but will affect results - is linked to exposure levels and the outcome