Cohort Study
Step 7: Seminar Discussion Questions
Carefully consider the following questions related to your work above. Write down your answers and be
prepared to discuss them in seminar.
- How and why the results of Q8 are different from the results of Q9? Give examples of the events that could have influenced the results.
- What would you have done to improve the design of this retrospective cohort study?
- What does the crude rate ratio tells us?
- What does the monotonic increase in rate ratio among various exposure groups in Q10 tells us? How does it influence our certainty about the results of this study?
- Why do we need to look at the age distribution of risk in the cohort (see Q11) an how should we interpret our findings?
- Design a prospective cohort study which would investigate the relationship between exposure to SUPERCLEAN and Susser Syndrome. Use information from the Study Design section to guide yourself through the necessary steps.
- Do you think the results of this cohort study are suggestive or conclusive about the effect of the SUPERCLEAN on neurologic morbidity?
- Is there a need to conduct further studies?
Questions for the Intellectually Curious 
- What does SIR in Q12 tells us?
- Why do you think SIR is lower than the crude rate ratio?
- Let us assume that Susser Syndrome was a reportable disease. In other words,
physicians and hospitals would be required to report all patients diagnosed with Susser
Syndrome to the Epiville Department of Health (this is a form of passive
surveillance). How would your data collection change if this were the case? What are
the advantages and disadvantages of such change, vis-a-vis hospital discharge data?
