EPBI 5101 Homework #4 1 Name: TUID: Homework #4: Cohort Studies A researcher conducted a well-funded, prospective cohort study in 2011, in which she collected data on a total of 450 women who worked at Abrutze Radiology1 in Houston, TX. After two years of follow-up, the researcher found that 80% of the Abrutze workers had received accidental low doses of radiation. Of the 80% of women who received the accidental low doses, 45% developed an aggressive form of uterine cancer within the two years. Of those women who did not receive the accidental radiation, 25 still went on to develop uterine cancer.

1. Construct a 2x2 table for this study. Clearly identify the exposure and outcome. (3 points) Total Total

2. Calculate the cumulative incidence rate per 1,000 people for the exposed group. (round to whole number)

3. Calculate the cumulative incidence rate per 1,000 people for the unexposed group. (round to whole number)

4. Calculate the Relative Risk comparing exposed to unexposed. (round to 2 decimals)

5. Is the exposure a risk factor or a protective factor? a. Risk factor b. Protective factor 1 Abrutze Radiology is a fictitious name. EPBI 5101 Homework #4 2

6. Provide a interpretation for the Relative Risk you calculated in question 4.

7. Describe one strength of the Abrutze Radiology cohort study. Make sure these are not general statements; they must relate directly to the Abrutze Radiology cohort study:

8. Describe one limitation of the Abrutze Radiology cohort study. Make sure these are not general statements; they must relate directly to the Abrutze Radiology cohort study