Questions 18-22 refer to the following information: Below are results from a case-control study of physical inactivity and the risk of coronary heart disease (CH D). There were 500 participants in the study. CHD Controls Total No exercise 127 110 237 73 190 263 200 300 500 The study researchers were concerned that diet may affect the association between physical activity and CH D, so they divided the study participants by whether or not they ate a high fat diet. Here are the results: Moderate/ high fat diet CHD Controls Total No Exercise 114 60 174 33 53 147 80 227 Low fat diet CHD Controls Total No Exercise 13 63 40 170 210 53 220 273 Question 18 2 pts The crude (overall) odds-ratio is 1.05 O 2.03 1.11 O 0.91 3.0 1.15 Question 19 1.5 pts The stratum-specific odds-ratio for moderate/high fat diet is O 2.03 3.0 1.05 1.15 O 0.91 1.11Question 20 1.5 pts The stratumspecic oddsratio for low fat diet is 1.05 2.03 1.15 3.0 Based on the stratum-specic odds ratios you calculated, what do you conclude? There is some association between exercise and CH D, but it is confounded by diet. There is some association between exercise and CH D, but it is modied by diet. There is no association between diet and CH D. The investigator did not need to stratify the data by diet. There is no association between exercise and CHD Question 48 2 pts Complete the sentence: Non-differential misclassication tends to bias study results _, while differential misclassication tends to bias study results Towards the null, towards the null Either away from or towards the null, either away from or towards the null Away from the null, towards the null Towards the null, away from the null Towards the null, either away from or towards the null Question 49 2 pts In a cohort study of throat cancer, 20,000 men and women were followed and observed for 10 years and information was collected regarding their alcohol consumption and whether or not they developed throat cancer. rr ' lcohol+ 9200 5163 14,363 ' Icohol 2700 2937 5637 11,900 8100 20,000 What is the relative risk of throat cancer among persons who drank alcohol? 1.34 1.87 2.00 1.86 Question 50 2 pts In a cohort study of throat cancer, 20,000 men and women were followed and observed for 10 years and information was collected regarding their alcohol consumption and whether or not they developed throat cancer. rr ' |cohol+ 9200 5163 14,363 ' Icohol 2700 2937 5637 1 1,900 8100 20,000 Interpret the relative risk None of the answer choices The excess risk of throat cancer in the entire population 2.00% Persons who drank alcohol were 1.34 times more likely to develop throat cancer compared to non-alcohol drinkers Persons who drank alcohol had a 1.34% excess risk of developing throat cancer compared to non alcohol drinkers Question 51 2 pts In a cohort study of throat cancer, 20,000 men and women were followed and observed for 10 years and Information was collected regarding their alcohol consumption and whether or not they developed throat cancer. r_r_ _9200 5163 14,363 _11,900 3100 20,000 What is the risk difference among persons who drank alcohol? None of the answer choices 161.55 per 1000 186.00 per 1000 115.34 per 1000 Question 52 0 pts Extra Credit: In a cohort study of throat cancer, 20,000 men and women were followed and observed for 10 years and information was collected regarding their alcohol consumption and whether or not they developed throat cancer. r_r_ __ What is the attributable risk percent among persons who drink alcohol? 23.6% None of the answer choices 33.7% 25.22%