title: Postmarketing studies of drug efficacy: when must they be randomized?
mesh_terms: D002986:Clinical Trials as Topic / Q000379:methods*; D005069:Evaluation Studies as Topic / Q000379:methods*; D006801:Humans; D011358:Product Surveillance, Postmarketing / Q000379:methods*; D011897:Random Allocation; D014481:United States