Question # 2: Odds Ratio and Relative Risk (20 points) A researcher would like to assess the relationship between an exercise program (Program A) that can prevent obesity among youth and a newer more rigorous program (Program B) that was developed by a group of middle school coaches. The students are assessed at the end of the school year. After addressing all ethical considerations and adjusting for potential confounders, the following results are obtained. Student BMI at the End of the School Year _ OvenNeight/ Obese Overweight/ Obese Pro- ram A _2_ i. Calculate the odds ratio (5 points) ii. Calculate the relative risk (5 points) iii. How do the two measures compare and what does this tell the researcher? (5 points) iv. What else should the researcher look for when interpreting these findings. (5 points) Question # 3: Incidence Density (20 points) A cohort study (hypothetical) was conducted to look at survival after experiencing a myocardial infarction (heart attack). Ten participants were followed for 3 years, resulting in the following table: Follow-up Time (Months! Event 3 Death 5 Censored 8 Death 12 Death 17 Censored 19 Censored 27 Death 32 Censored 36 Followed until end of study period 36 Followed until end of study period i. What is the cumulative survival probability at the end of the follow-up period? (5 points) ii. Using the same data, calculate the overall death rate per 100 person-years. (5 points) iii. Calculate the rates separately for each of the 3 years of follow-up. (10 points) iv. Given the information above, is it appropriate to report an overall 3-year death rate for this study? Why or why not? (5 points) Question # 4: Attributable Risk (20 points) A hypothetical cohort study looked at the association between family history and the risk of developing Alzheimer's disease. The results were as follows: Alzheimer's No Alzheimer's Totals Incidence of Disease Disease AD Famil Histo 1,950 2,000 25 oer1,000 No Family 2 ,975 3, 000 8.3 per 1,000 Histor i. Calculate the attributable risk for Alzheimer's disease due to family history. Interpret the calculation in words. (5 points) ii. Assume the prevalence of family history in the general population is 5%. Calculate the population attributable risk and interpret it in words. (5 points) iii. Now assume the prevalence of family history in the general population is 25%. Calculate the population attributable risk and interpret it in words. (5 points) iv. What effect does this change have on the estimate of the population attributable risk? Discuss the relationship between the population prevalence of exposure and the population attributable risk. Why is it important to understand this relationship as a public health professional? (5 points)