Epidemiological Tests Flashcards
This type of study is a snapshot in time
cross-sectional
This type of study is retrospective (looks backward in time)
case control
This type of study is prospective (looks forward in time)
cohort
What are 3 advantages of cross-sectional studies?
- cheap
- not time consuming
- many outcomes and exposures can be assessed
What are 3 disadvantages of cross-sectional studies?
- no causal inferences (exposure and outcome determined at same time)
- snapshot of one time point
- recall biases
What is the purpose of a cross-sectional study?
descriptive, but can investigate associations between exposures and outcomes
What is the purpose of a case-control study?
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)
What are 3 advantages of a case-control study?
- good for rare outcomes
- good for outcomes with long periods between exposure and outcome
- cheaper
What are 3 disadvantages of a case-control study?
- poor for rare exposures
- subject to bias and confounding
- difficult to identify appropriate controls
What is the purpose of a cohort study?
to follow a cohort of people prospectively to determine which initial participants exposure characteristics (risk factors) are associated with a disease outcome
What are 3 advantages of a cohort study?
- exposure before outcome (establishing temporality)
- subjects selected into cohort before having outcome
- can study several outcomes for each exposure
What are 3 disadvantages of a cohort study?
- expensive and time consuming
- inefficient for rare diseases or diseases with long latency
- loss to follow up