title: In search of the sample: recent experiences of a trial team in orthodontics.
abstract: Randomised clinical trials are commonly undertaken in medical and dental research. However, few authors discuss the difficulties associated with such studies, including costs, ethical issues and recruitment of an adequate number of patients. There is little information available on the number of studies which are terminated early as a result of these issues, but it seems likely that at least 10% of clinical studies never reach completion. This paper reviews two nationally funded clinical studies which were terminated early. It highlights the problems associated with patient recruitment and also some issues which may benefit researchers undertaking similar studies in the future.
authors.affiliation: Department of Orthodontics, UCL Eastman Dental Institute, London, United Kingdom. S.Cunningham@eastman.ucl.ac.uk
authors.forename: Susan
authors.initials: S
authors.lastname: Cunningham
authors.forename: David
authors.initials: D
authors.lastname: Bearn
authors.forename: Philip
authors.initials: P
authors.lastname: Benson
authors.forename: Ama
authors.initials: A
authors.lastname: Johal
authors.forename: Declan
authors.initials: D
authors.lastname: Millett
authors.forename: Kevin
authors.initials: K
authors.lastname: O'Brien
authors.forename: Friedy
authors.initials: F
authors.lastname: Luther
mesh_terms: D057239:Early Termination of Clinical Trials; D006801:Humans; D015337:Multicenter Studies as Topic; D009970:Orthodontics; D018579:Patient Selection; D016032:Randomized Controlled Trials as Topic