Methodological problems with population cancer studies: The forgotten confounding factors

Abstract

Among clinical physicians it is the population study that is considered to be the “gold standard” of medical evidence concerning acceptable treatments. As new information comes to light concerning the many variables and confounding factors that can affect such studies, many older studies lose much of their original impact. While newer population studies take into consideration a far greater number of confounding factors many are still omitted and a number of these omitted factors can have profound effects on interpretation and validity of the study. In this editorial, I will discuss some of the omitted confounding factors and demonstrate how they can alter the interpretation of these papers and their clinical application.

Nutritional Solutions to Reduce Risks of Negative Health Impacts of Air Pollution

“…In another trial performed in Linxian province, China, the effects of an antioxidant mixture containing vitamin E, ß-carotene and selenium were examined on the prevention of gastric cancer. In contrast to the ATBC and CARET studies, the highest anticancer effect of the antioxidant mixture was observed in smokers [ 87 ].…”