A recent newspaper article titled “Study links soda to diabetes in women” describes a high profile study of great concern to executives in the soft drink industry. This study of 91,000 nurses finds “women drinking one or more sugar-sweetened soft drinks a day were twice as likely to develop diabetes as women who drank less than one a month.” It goes on to say that pure fruit juice and diet soft drinks were not linked to diabetes, but fruit “punch” (fruit juice with sugar and water added) was linked.

(a) The age of the women was a potential confounding factor, since younger women tend to prefer different drinks than older women. But the researchers properly took this factor into account so it didn’t cause bias in the study results. Instead of just comparing all women who drank sugary sodas with all women who didn’t drink sugary sodas, what type of comparison(s) would the researchers need to make so that age differences don’t bias the study’s conclusions?

(b) A soft drink industry spokesman criticizes the study saying that there are some additional important confounding factors that were not completely taken into account. Give an important confounding factor, other than age, that would play a role here.

(c) Explain why the fact that all the subjects in the study were nurses would not be a confounding factor.

(d) Would genetics be a likely confounding factor? Explain why or why not.

Answer rating: 100% (QA)

A Instead of just comparing all women who drank sugary sodas with all women who didnt drink sugary s... View the full answer