Cohort Study Design
Suppose that you have been hired by university student health services to design a prospective cohort study to assess the following hypothesis among undergraduate students: Raw sushi consumption increases the risk of acute diarrheal episodes.
Be sure that your design addresses the following elements:
1. Refine the study hypothesis so that it is as specific as possible and contains all elements of a “good” hypothesis.
2. How will you find and recruit participants?
o Are there any exclusion criteria that you would apply?
3. Will the study be retrospective or prospective?
4. How will you define the exposure of interest?
o How will you collect the information on exposure?
o How will you define the unexposed condition?
5. How will you define the outcome?
o How will you collect information on acute diarrhea?
o How often will subjects be evaluated/followed?
6. What other information do you want to know about participants that may be related to the exposure of interest and/or the outcome (potential confounders)? Of these, what will you be able to collect and what will you be unable to collect?
7. Which measures of disease frequency and association will you calculate?
8. What are the strengths and limitations of your study?
o What limitations could be removed by using a different study design?
9. What other information would you like to know in order to design this study?
