Maddox

Biology

30 July, 15:07

Why are controls needed in a case-control study?

A. They increase the size of the study so that risk estimates are significant

B. They are less likely to have recall bias issues

C. They do not have the exposure of interest and allow for the estimation of disease frequency among the unexposed

D. They do not have the outcome of interest and allow for estimation of exposure frequency among those without the disease