Question

The primary difference between an experimental study (e.g., an RCT) and a prospective cohort study is:

A. In experimental studies, researchers can directly measure the difference in incidence of the outcome that is associated with exposure

B. In experiemental studies, participants are first categorized according to exposure, then followed over time to see who gets the outcome

C. In experimental studies, the researchers allocate exposures to participants

D. In experimental studies, the researchers study exposures that were already occurring regardless of their actions

Answer 1

C.in experimental studies ,the researchers allocate exposures to participants.

Random allocation(randomization) is an essential part of good experimental studies.

In both of these,Subjects must be free of the outcome at the start of the Subjects must be free of the outcome at the start of the study.People are grouped into “exposed”/ “not exposed”categories.Groups are followed for a period of time to determine Groups are followed for a period of time to determine outcome.