An epidemiological study is conducted to learn about the relationship between celiac disease and colon cancer. Suppose there are 77 cases of colon cancer in 68,000 person-years in persons with celiac disease and 54 cases of colon cancer in 215,000 person-years in those without celiac disease. (The overall rate in both groups combined = 131 cases in 283,000 person-years overall.) Use this information to answer questions 1–3.
- Calculate the rate of colon cancer in the celiac group (R1), in the no celiac group (R0), and overall (R). Express all rates in “per 100,000 person-years.”
- Calculate and interpret the relative risk of colon cancer associated with celiac disease.
- Calculate and interpret the attributable risk of colon cancer associated with celiac disease.