In Reply Although there are no specific guidelines for the use of a placebo in clinical trials of patients with Crohn disease, both the US Food and Drug Administration and the European Medicines Agency have released guidance documents on the choice of the control group, including a decision tree on how to identify the most appropriate one.1,2 Both agencies classify 5 types of control groups: placebo, active treatment, no treatment, dose-comparison, and external control.
Lazzerini M, Martelossi S, Ventura A. Use of Placebo in a Trial of Thalidomide for Pediatric Crohn Disease—Reply. JAMA. 2014;311(12):1251-1252. doi:10.1001/jama.2014.1278