title: Defining a clinically meaningful effect for the design and interpretation of randomized controlled trials.
abstract: OBJECTIVE
  This article captures the proceedings of a meeting aimed at defining clinically meaningful effects for use in randomized controlled trials for psychopharmacological agents.
  
  
  METHODS
  Experts from a variety of disciplines defined clinically meaningful effects from their perspectives along with viewpoints about how to design and interpret randomized controlled trials.
  
  
  METHODS
  The article offers relevant, practical, and sometimes anecdotal information about clinically meaningful effects and how to interpret them.
  
  
  METHODS
  The concept for this session was the work of co-chairs Richard Keefe and the late Andy Leon. Faculty included Richard Keefe, PhD; James McNulty, AbScB; Robert S. Epstein, MD, MS; Shelby D. Reed, PhD; Juan Sanchez, MD; Ginger Haynes, PhD; Andrew C. Leon, PhD; Helena Chmura Kraemer, PhD; Ellen Frank, PhD, and Kenneth L. Davis, MD.
  
  
  RESULTS
  The term clinically meaningful effect is an important aspect of designing and interpreting randomized controlled trials but can be particularly difficult in the setting of psychopharmacology where effect size may be modest, particularly over the short term, because of a strong response to placebo. Payers, regulators, patients, and clinicians have different concerns about clinically meaningful effects and may describe these terms differently. The use of moderators in success rate differences may help better delineate clinically meaningful effects.
  
  
  CONCLUSIONS
  There is no clear consensus on a single definition for clinically meaningful differences in randomized controlled trials, and investigators must be sensitive to specific concerns of stakeholders in psychopharmacology in order to design and execute appropriate clinical trials.
authors.affiliation: Dr. Keefe is Professor of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, North Carolina; Dr. Kraemer is with Stanford University (Emerita), Stanford, California, and University of Pittsburgh, Pittsburgh, Pennsylvania; Dr. Epstein is with Epstein Health, Woodcliff Lake, New Jersey; Dr. Frank is with the Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Dr. Haynes is with Eli Lilly and Company, Indianapolis, Indiana; Dr. Laughren is with Laughren Psychopharm Consulting, LLC, Rockville, Maryland; Dr. McNulty is Executive Director at MHCA/OASIS-RI, Providence, Rhode Island; Dr. Reed is with Duke Clinical Research Institute, Durham, North Carolina; Dr. Sanchez is Analyst, Ladenburg Thalmann & Co., New York, New York; and Dr. Leon was Professor of Biostatistics in Psychiatry at Weill Cornell Medical College, New York, New York.
authors.forename: Richard S E
authors.initials: RS
authors.lastname: Keefe
authors.forename: Helena C
authors.initials: HC
authors.lastname: Kraemer
authors.forename: Robert S
authors.initials: RS
authors.lastname: Epstein
authors.forename: Ellen
authors.initials: E
authors.lastname: Frank
authors.forename: Ginger
authors.initials: G
authors.lastname: Haynes
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Laughren
authors.forename: James
authors.initials: J
authors.lastname: McNulty
authors.forename: Shelby D
authors.initials: SD
authors.lastname: Reed
authors.forename: Juan
authors.initials: J
authors.lastname: Sanchez
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Leon
keywords: Clinically meaningful effect; psychopharmacology drug trials