title: Randomized controlled clinical trial. National Eye Institute workshop for ophthalmologists. Why do we need controls? Why do we need to randomize?
mesh_terms: D002986:Clinical Trials as Topic; D003139:Common Cold; D003327:Coronary Disease; D004036:Diet, Atherogenic; D006331:Heart Diseases; D006801:Humans; D008875:Middle Aged; D010919:Placebos; D012107:Research Design
chemical_list: D010919:Placebos