WHEN IS A NEGATIVE STUDY NOT NEGATIVE

Results of Phase III randomized clinical trials can be categorized int o three groups: positive, null, and negative. The jargon used in discu ssing results of comparative studies requires clarification because mi sclassification can result in incorrect interpretation, A positive res ult indicates that the experimental therapy(ies) is(are) superior to s tandard therapy, A null result indicates that no statistically signifi cant difference between therapies was found; hence, standard therapy s hould not be replaced, A negative result indicates that the experiment al therapy had a deleterious effect compared to standard therapy, This article presents a discussion of these categories and examples of eac h. (C) 1997 Elsevier Science Inc.