2 Study Designs Flashcards
What is the AAAA framework?
Assess - what type of study?
Access - where is the best evidence?
Appraise - quality of evidence
Act - is this relevant to my clinical practice?
Who made the link between Thalidomide and congenital defects?
Lenz and McBride in 1961
What study would you use to answer a frequency of disease who is affected question?
ecological; cross section
What study would you use to answer an aetiology / risk factor question?
case - control or cohort study
What study would you use to answer an effectiveness question?
RCT
What study would you use to answer a diagnosis question?
special cross sectional
test accuracy study
What study would you use to answer a patient experience question?
qualitative study
What is a case report study?
a detailed report of an unusual ‘condition’ or ‘uccurence’ in a single moment
What is a case series?
a detailed reoport of an unusual ‘condition’ or occurrence in several practices
What is a cross-sectional study?
information is collected (planned), in a defined population at one point in time
What is an ecological sudy?
information is collected from population groups to compare disease frequencies
What are the two different ways that data could be collected in an ecological study/
in the same population but at different points in time
between different populations at the same point in time
What are the sub-divisions of studies?
descriptive anatlytical (observational or interventional)
Name the 4 types of descriptive sudies
case report
case series
cross-sectional study
ecological study
What are the characteristics of descriptive studies
observational
often precede analytic studies investigating disease in aetiology
What are the characteristics of analytical studies?
use comparisons of groups
aims to establish whether an exposure causes an outcome
What is an observational analytical study?
researcher is an observer of exposures and outcomes
What is an interventional analytical study?
researcher allocates exposure and observes medicine
What are the 2 types of observational analytical study?
case control
cohort study
What is a case control study?
investigates multiple exposure, but one outcome
recruitment is based on the presence or absence of outcome, doesn’t have to wait for one to occur
active case finding overcomes the rareness of outcomes
What is a cohort study?
investigates one exposure to multiple outcomes
have to wait for outcome to occur
What questions should be used when deciding to do a cohort or case-control trial?
how many exposures?
how many outcomes?
time between exposure and outcome?
is outcome rare or common?
What are randomised controlled trials used to invetigate?
effectiveness
