Usefulness of correlation analyses in the epidemiology of stomach cancer

To detect the risk factors for stomach cancer, we performed correlation analyses among stomach cancer mortality, food consumption, and other related factors using population-based data. Cereals (especially rice) and salty foods (particularly salted and dried fish) were related positively to stomach cancer mortality; milk and milk products, meat, oils and fats, and fruits were related inversely to it. We believe these results show that factors related positively to stomach cancer mortality could play a role in risk and those related inversely could be protective in the etiology of stomach cancer. As complementary methods in case-control and cohort studies, correlation analyses seemed useful when variation of exposures to risk factors is small between individuals within a population but is relatively large between populations.