To test the efficacy of vitamin C in preventing colds, army recruits are randomly assigned to one of two groups: one in which 500 mg of vitamin C is administered daily, and one in which 500 mg of a placebo is administered daily. Both groups are followed to determine the number and severity of subsequent colds. Which of the following study designs most appropriately characterizes this situation?
A) Cross-sectional study
B) Case-control study
C) Prospective cohort study
D) Historical prospective cohort study
E) Clinical trial

Question

Quizplus · Accepted Answer

This is a clinical trial because it involves the random assignment of participants to receive either the treatment (vitamin C) or a placebo, and then follows them to observe the outcomes.

To Test the Efficacy of Vitamin C in Preventing Colds