title: Shortcomings of the National Crohn's Disease Study: the exclusion of azathioprine without adequate trial.
mesh_terms: D001379:Azathioprine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002986:Clinical Trials as Topic / Q000592:standards*; D003424:Crohn Disease / Q000188:drug therapy*; D004311:Double-Blind Method; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D006801:Humans; D015122:Mercaptopurine / Q000627:therapeutic use; D010919:Placebos; D011241:Prednisone / Q000627:therapeutic use; D011897:Random Allocation; D012107:Research Design / Q000592:standards*; D012460:Sulfasalazine / Q000627:therapeutic use; D014481:United States
chemical_list: D010919:Placebos; D012460:Sulfasalazine; D015122:Mercaptopurine; D001379:Azathioprine; D011241:Prednisone