Question

All changes saved in Drive Question 26: Which of the studies (case-control or cohort) has a larger sample size, costs r and takes longer to complete? For the first six issues below, cite which study is best to use (case-control or cohort study). For last 3 types of bias, cite which study is less likely to have that particular type of bias (case-control or cohort). Answer 26 1) Study a rare disease 2) Study a rare exposure 3) Study multiple exposures 4) Study multiple outcomes 5) Study progression of the illness 6) Calculate disease rates 7) Recall bias 8) Loss to follow-up 9) Selection bias Oustion 27 Which type of study tcohort or case-control) would you have done first? Why? What would your second study be and why? Question 28 Which of the following criteria for causality are met by the evidence presented 4.

Answer 1

Cohort study has a larger sample size, more costs and longer time frame in comparison to case-control studies.

1. Study a rare disease- Case-control studies because subjects are chosen from the population by their outcome status.

2. Study a rare exposure- Cohort studies because subjects are chosen by their exposure status in cohort studies.

3. Study multiple exposures: Case-control studies because case-control study is better for multiple exposures to be assessed for one outcome

4. study multiple outcomes: Cohort study because multiple outcomes can be examined simultaneously.

5. Study progression of the illness: Case-control studies because subjects are chosen from the population by their outcome status.

6. Calculate disease rates: Cohort study because disease rates can be calculated.

7. Recall bias: Less likely chance of its presence in Cohort study

8. Loss to follow-up: Less likely chance of its presence in Case-control study

9. Selection Bias: Less likely chance of its presence in Cohort study