Study designs: analytical

Question 1

Cross sectional study: describe

Answer 1

take exposure and outcome data AT THE SAME TIME

relationship can be seen between them

but can’t determine direction

Question 2

do cross sectional studies show prevalence

Answer 2

yes

Question 3

do cross sectional studies show incidence?

Answer 3

no - just a snapshot

Question 4

2 additional advantages of cross sectional studies

Answer 4

quick/cheap/easy

generate hypotheses

Question 5

are cross sectional studies good for rare diseases, why so

Answer 5

no

as they’re rare and unlikely to come up

Question 6

example of cross sectional study for teenage alcohol consumption vs depression?

Answer 6

teens were surveyed about whether they consume alcohol and whether they’ve been diagnosed with depression.

Question 7

describe case control studies

Answer 7

info collected at same time but
case/control data is specifically looked at first. (often matched)
then exposure prevalence is determined within cases and controls.

Question 8

what statistic does case control studies look at

Answer 8

odds ratio

Question 9

can you determine incidence with case control

Answer 9

no

Question 10

is case control good for rare diseases? why so

Answer 10

yes - as you can select them from the start

Question 11

additional advantage and disadvantage of case control

Answer 11

helps determine whether an exposure is a risk factor/potential cause

recall bias (when determining exposure)
selection bias (if making mathces)

Question 12

case control example of teenage alcohol consumption vs depression?

Answer 12

teens with and without depression are identified and matched based on other characteristics. Prevalence of alcohol consumption is determined in cases and controls.

Question 13

cohort study: common ground?

Answer 13

starts with exposure (or not), then looks at whether cases/controls come about

Question 14

what statistic do cohort studies look at

Answer 14

relative risk

Question 15

describe prospective cohort study

Answer 15

disease free cohort
look at exposure in present time
then follow over time to see if people develop disease

Question 16

if you increase time period, what’s a pro and con?

Answer 16

more info can be collected

but higher chance of loss to follow up

Question 17

are PCS good for rare risk factors? why so

Answer 17

yes as you can pick them as a starting point

Question 18

are PCS good for rare diseases? why so?

Answer 18

no. as they’re unlikely to develop

Question 19

are PCS good for common diseases? why so

Answer 19

yes. as they’re likely to develop

Question 20

why is prospective cohort study best evidence for causation out of analytical studies

Answer 20

as you can follow disease progression in real time

Question 21

two other disadvantages of prospective cohort studies

Answer 21

confounding

selection bias

Question 22

prospective cohort study example of teenage alcoholism and depression

Answer 22

start with population of teens without depression. Whether individuals consume alcohol or not are noted. Individuals in each group are tracked to see if they develop depression

Question 23

describe retrospective cohort study

Answer 23

look at past exposure. then follow up in future to see if disease develops