Epidemiology for Public Health Practice 5th Edition by Robert Friis,Thomas Sellers

Exercise 2

A case-control study was carried out in which 120 of 200 cases of stomach cancer and 50 of 200 control subjects gave a history of exposure to radiation. In further analysis, however, the investigators noticed that 50% of the cases but only 25% of the controls were men. What would be a practical and efficient way to eliminate differences between cases and controls with respect to sex?