You are a researcher interested in investigating the association between obesity and chronic heart disease (CHD). You conduct a case-control study of hospital patients with to investigate this association and tabulate your results as the following Cases with CHD Controls without CHS total Obese patients 26 190 216 Non-obese patients 91 2249 2340 Total 117 2439 2556 a. Calculate and interpret the OR b. You are given information that diabetes may confound or modify the association between obesity and CHD. Statifying your cases and controls, you tabulate the following information. non-diabetic patients Cases with CHD Controls without CHD Obese patients 40 111 Non-obese patients 64 1574 Non-diabetic patients Cases with CHD Controls without CHD Obese patients 40 111 Non-obese patients 64 1574 Diabetic patients Cases with CHD Controls without CHD Obese patients 8 57 Non-obese patients 27 865 c. Calculate and interpret the stratified OR d. Is there statistical evidence for confounding or effect modification? What estimates should you provide? e. Regardless of your previous answer, walk through the definition of confounding. Does it theoretically make sense that diabetes confounds the relationship between obesity and CHD? (I am not testing your knowledge of obesity, CHD or diabetes, just your ability to logically think about confounding)