15 - Case-Control Study Flashcards
In terms of analysis, what is the difference between case-control and cohort studies?
Case-control cannot do IRR but cohort can do ORR and IRR
Why would you not investigate leukaemia with a cohort study?
It is a really rare outcome, would have to collect lots of person years. Better to use case-control
Briefly outline a case-control study and why we use them?
How do you work out an odds ratio?
How do you work out 95% CI?
Using the following data, work out the IRR?
How is the precision of OR affect?
What is a nested case-control study?
Collection of data from evolving outcome and exposure of a concurrent or prospective cohort study
What are the different types of cohort and case-control study?
What are the different types of information bias and what effects do they have on analysis?
What are the different types of information bias and what effects do they have on analysis?
How can confounding be minimised?
- Matching using important confounders e.g age and gender
- Adjusted for by analysing with logisitic regression so adjusted OR’s
Compare cohort and case-control studies.
What are the issues for case control and cross-sectional studies?
Why would you choose a case-control study over a cohort study for the association of vitamin K with chronic leukaemia?
- Long time for outcome if cohort
- Can explore lots of different exposures in the study, not just one
- Rare disease
How would you interpret this data?
- There is a 25% increased chance of developing childhood leukaemia when there is pethidine/vitamin K administration
- Null hypothesis of 1 is in the 95% CI so p>0.05 therefore you cannot reject the null hypothesis
- There is also a chance that the risk of developing cancer is decreased by up to 11% or increased by up to 73% with the administration of the medication
