Study types and stuff

Question 1

Cohort study - what is it

Answer 1

Get a lump of people with no disease
No exposing people to stuff - just see what they do naturally and compare them - like look at who smokes and who doesnt

See who gets SCLC in both groups.

So going forward in time - longitudinal

Question 2

Case control study

Answer 2

So you have your group of lads.
Some have SCLC and some dont

See who smoked when they were young and who didnt
See if there are more people with SCLC among those who smoked

going back in time here

Question 3

Randomised control trial

Answer 3

RANDOM people
RANDOMLY put in groups
RANDOMLY give one group something Rx or control

See who RANDOMLY dies

Question 4

Cross sectional study

Answer 4

at a specific point in time

analyse who does and doesn’t have the disease and see who was and wasn’t exposed to the bad thing

Question 5

Ecological study

Answer 5

look at prevalence of disease vs location (geography)
or vs time

trends n stuff

Question 6

Bias - what is it

Answer 6

A systematic deviation from the true
estimation of the association between
exposure and outcome

Question 7

selection bias

Answer 7

error in participant selection
ie accidentally putting all of the women in the control group under the supervision of Dr X and all the men in the other one. By accident

Question 8

information bias

Answer 8

error in getting info - ie measurement

Question 9

association - what to consider?

Answer 9

Bias
Chance
Confounding

Question 10

what do you need to say theres causality

Answer 10

Strength of association
Dose-response [the higher the exposure, the higher the risk of disease]
Consistency
Temporality [does exposure precede the outcome?]
Reversibility (experiment)
Biological plausibility