Chapter 4.2, Problem 43E

To determine

To explain how confounding makes it unreasonable to conclude that eating seafood causes a reduction in the risk of colon cancer, based on this study.

Explanation of Solution

It is given that the researchers tracked the $22000$ male physicians for $22$ years. And the study found out that those who reported eating seafood of any kind at least five times per week had a $40\%$ lower risk of colon cancer than those who said they ate seafood less than once a week. Thus confounding makes it unreasonable to conclude that eating seafood causes a reduction in the risk of colon cancer because the study was taken place for that is fish good for the gut or not and it shifted to the seafood and the colon cancer. Thus mixing of the facts can give wrong results. And also there should have been separate studies to find out the accurate results and proper conclusions.