Discovery of adverse drug reactions. A comparison of selected phase IV studies with spontaneous reporting methods.

Following a Food and Drug Administration review of three major phase IV studies involving from 7,607 to 22,653 persons, it was determined that none of the studies resulted in the detection of new adverse drug reactions (ADRs). For two of the three drugs studied, new ADRs were identified after approval. The discovery of these new ADRs was attributed to physician case reports obtained through concurrently operating spontaneous reporting mechanisms. ( JAMA 1983;249:2226-2228)