title: When is a negative study not negative?
abstract: Results of Phase III randomized clinical trials can be categorized into three groups: positive, null, and negative. The jargon used in discussing results of comparative studies requires clarification because misclassification can result in incorrect interpretation. A positive result indicates that the experimental therapy(ies) is(are) superior to standard therapy. A null result indicates that no statistically significant difference between therapies was found; hence, standard therapy should not be replaced. A negative result indicates that the experimental therapy had a deleterious effect compared to standard therapy. This article presents a discussion of these categories and examples of each.
authors.affiliation: Radiation Therapy Oncology Group Statistical Unit, Philadelphia, PA 19107-2914, USA.
authors.forename: C
authors.initials: C
authors.lastname: Scott
authors.forename: T
authors.initials: T
authors.lastname: Wasserman
mesh_terms: D017326:Clinical Trials, Phase III as Topic / Q000145:classification*; D003627:Data Interpretation, Statistical; D006801:Humans; D016032:Randomized Controlled Trials as Topic / Q000145:classification*; D016896:Treatment Outcome