The Physicians' Health Study is a very large, randomized study designed to "test the effects of low-dose

aspirin... in the prevention of cardiovascular disease (CVD)." An outcome of interest in the Physicians' Health Study was whether the subjects developed ulcers or not. Of the 11,034 physicians who took the placebo, 138 developed ulcers during the study. Of the 11,037 physicians who took aspirin, 169 developed ulcers.

Organize the counts in a well-labeled 2 x 2 table. Placebo Aspirin Total Ulcer? Yes n n I No I E E Total n n n