Principles of Epidemiology Calculations and Interpretations: Answer the following questions in the space provided. Show all of your work. 1. Evidence of an increased risk of lung cancer associated with cigarette smoking was sought by Doll and Hill. In one study, 749 lung cancer cases were matched by age, and gender to 749 controls; 722 of the cases and 622 of the control had a history of smoking cigarettes. a. Name the type of study. (1 point) b. Create the appropriate 2X2 table for the study. (2 points) c. Calculate the appropriate measure of association for the study. (4 points) d. Interpret the results. (2 points) 2. In another study, the smoking habits of 34,445 male physicians were obtained by mailed questionnaires. Deaths among these physicians over the subsequent years were identified though contact with the office of the Registrar General. The death rates from lung cancer of these physicians classified by smoking habits were : Standardized Death Rates per 1000 Persons Aged 35 or More per Year Nonsmokers 0.08 Cigarette Smokers 0.93 a. Name the type of study. (2 points) b. Calculate the appropriate measure of association for the study. (6 points) c. Interpret the results (2 points) 3. Annual Death Rates per 100,000 Persons Exposure Category Heavy Smokers Nonsmokers Lung Cancer Coronary Heart Disease 156 659 7 402 a. Calculate the relative risk from Lung Cancer Mortality for Heavy Smokers compared to nonsmokers. ( 4 points) b. Calculate the attributable risk of Lung Cancer from smoking. (4 points) c. Interpret the results. (2 points) d. Calculate the percent attributable risk of Coronary Heart Disease due to smoking (4 points) e. Interpret the results. (2 points) 4. Convert the following incidence rates to attributable risks using the additive model: (5 points) Factor B - Incidence Rates Attributable Risks Factor A Factor A _ + 3.0 9.0 _____________________________________ + 18.0 _ + __________________________________ 5. Calculate the concordance rate for the following data: (5 points) Twin 1 Twin 2 Has Leukemia Does Not Have Leukemia Has Leukemia 16 2 Does Not Have Leukemia 24 38 6. Compare/contrast case control and cohort studies. (8pts) 7. Using the data below, compute lung cancer mortality rates, rate ratios, and rate differences for each smoking category. What do each of these measures mean? (10 points) Daily # of cigs Deaths from lung cancer Person-yrs at risk 0 5 42,800 1-14 32 38,600 15-24 74 38,900 25+ 77 25,100 All smokers 183 102,600 Total 188 145,400 Mortality rate per 1000 person-yrs Rate Ratio Rate difference per 1000 ref ref