Am not sure what this could be, any help will be appreciated.

Question

Suppose that a study is being planned to determine whether obesity is a risk factor for diabetes. The researchers are aware that:

1) Females are more likely to be obese than males.

2) Females have a higher risk of diabetes than males.

Failure to control for sex when assessing the association between obesity and diabetes could result in which of the following. (a)effect modification (b)confounding (c) selection bias (d)differential misclassification.

I know that the association btw the obesity and diabetes is different among sex strata and failure to adjust can leads to an effect modification but I also think that it could be a selection bias since the research knew before the start of the study and failed to control for it.

Answer 1

Selection bias would not be a problem, yet, as the study is just being suggested, and no subjects have been selected.