Epidemiological study design Flashcards
What are the 5 main types of study design?
5 main types of study design:
1) Observation –> case-control, cohort
2) Interventional –> Randomised Controlled Trial
3) Ecological study (studies of risk-modifying factors on health or other outcomes based on populations defined either geographically or temporally)
4) Cross-sectional study (analyses data from a population at a specific point in time –> similar to case control but over a period of time)
Odds ratio best used for what? Case control or cohort study?
Case-control study
How to calculate odds ratio?
Odds ratio = (Odds of exposure in cases) / (Odds of exposure in controls)
What is an ecological study?
Uses population level data i.e mortality rates to study relationships but not causes. It is also subject to ecological fallacy & bias.
What is a cross-sectional study?
Prevalence study which looks at relationships but not causes. It’s a one point of time study.
What is a case-control study?
Looks at people with a disease (case) and compares with a control (matched). Retrospective.
What is a cohort study?
Incidence study which follows a group of people over a period of time.
What is an intervention study?
Compare intervention group to non-intervention group i.e giving a drug and seeing the effects.
What is an ecological fallacy? Give an example
It’s a formal fallacy in the interpretation of statistical data that occurs when inferences about the nature of individuals are deduced from inferences about the group to which those individuals belong.
An example of this is Simpson’s paradox: a trend appears in several different groups of data but disappears or reverses when these groups are combined
What criteria is used to establish a causal association between variables?
Bradford-Hill criteria
Which study is best used for the study of attributable risk?
Cohort study
