Question

Brown and coworkers (2003) designed a study to determine the efficacy of immunotherapy with ant venom for treating ant stings. The study involved a group of 68 adults who were allergic to ant stings; each subject was randomly assigned to receive either venom immunotherapy or a placebo. After a sting challenge in which any reactions were recorded, the group originally on the placebo was given the venom immunotherapy, and after a sufficient time, they too were given a sting challenge.

Choose all of the answers that apply to this particular study design.

		a) Placebo
		b) Randomized
		c) Controlled d) Cohort study
		e) Clinical Trial
		f) Classic Cross-over

Answer 1

a) Placebo - Experiment in which a group of subjects that receives a sham treatment.

c) Controlled - An experiment in which two groups are used for comparison purpose.

f) Classic cross-over - It is a longitudinal study in which subjects receive a sequence of different treatments (or exposures)