Epidemiological Tests

Question 1

This type of study is a snapshot in time

Answer 1

cross-sectional

Question 2

This type of study is retrospective (looks backward in time)

Answer 2

case control

Question 3

This type of study is prospective (looks forward in time)

Answer 3

cohort

Question 4

What are 3 advantages of cross-sectional studies?

Answer 4

1. cheap
2. not time consuming
3. many outcomes and exposures can be assessed

Question 5

What are 3 disadvantages of cross-sectional studies?

Answer 5

1. no causal inferences (exposure and outcome determined at same time)
2. snapshot of one time point
3. recall biases

Question 6

What is the purpose of a cross-sectional study?

Answer 6

descriptive, but can investigate associations between exposures and outcomes

Question 7

What is the purpose of a case-control study?

Answer 7

To estimate odds by retrospectively determining the exposure to the risk factor of interest for patients who have a disease (cases) and patients who don’t have a disease (controls)

Question 8

What are 3 advantages of a case-control study?

Answer 8

1. good for rare outcomes
2. good for outcomes with long periods between exposure and outcome
3. cheaper

Question 9

What are 3 disadvantages of a case-control study?

Answer 9

1. poor for rare exposures
2. subject to bias and confounding
3. difficult to identify appropriate controls

Question 10

What is the purpose of a cohort study?

Answer 10

to follow a cohort of people prospectively to determine which initial participants exposure characteristics (risk factors) are associated with a disease outcome

Question 11

What are 3 advantages of a cohort study?

Answer 11

1. exposure before outcome (establishing temporality)
2. subjects selected into cohort before having outcome
3. can study several outcomes for each exposure

Question 12

What are 3 disadvantages of a cohort study?

Answer 12

1. expensive and time consuming
2. inefficient for rare diseases or diseases with long latency
3. loss to follow up