title: Issues in the registration of clinical trials.
abstract: Public concerns about the perils associated with incomplete or delayed reporting of results from clinical trials has heightened interest in trial registries and results databases. Here we review the current status of trial registration efforts and the challenges in developing a comprehensive system of trial registration and reporting of results. ClinicalTrials.gov, the largest trial registry with 36 249 trials from approximately 140 countries, has procedures in place to help ensure that records are valid and informative. Key challenges include the need to minimize inadvertent duplicate registrations, to ensure that interventions have unambiguous names, and to have a search engine that identifies all trials that meet a user's specifications. Recent policy initiatives have called for the development of a database of trial results. Several issues confound the implementation of such a database, including the lack of an accepted format or process for providing summaries of trial results to the public and concerns about disseminating data in the absence of independent scientific review.
authors.affiliation: National Library of Medicine, National Institutes of Health, US Department of Health and Human Services, Bethesda, Md, USA. dzarin@mail.nih.gov
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Zarin
authors.forename: Nicholas C
authors.initials: NC
authors.lastname: Ide
authors.forename: Tony
authors.initials: T
authors.lastname: Tse
authors.forename: William R
authors.initials: WR
authors.lastname: Harlan
authors.forename: Joyce C
authors.initials: JC
authors.lastname: West
authors.forename: Donald A B
authors.initials: DA
authors.lastname: Lindberg
mesh_terms: D002986:Clinical Trials as Topic / Q000941:ethics / Q000592:standards; D016208:Databases, Factual; D033181:Information Dissemination; D016247:Information Storage and Retrieval; D038622:Internationality; D009317:National Library of Medicine (U.S.); D012042:Registries / Q000592:standards / Q000706:statistics & numerical data; D014481:United States