title: Feasibility of surgical randomised controlled trials with a placebo arm: a systematic review.
abstract: OBJECTIVE
  To find evidence, either corroborating or refuting, for many persisting beliefs regarding the feasibility of carrying out surgical randomised controlled trials with a placebo arm, with emphasis on the challenges related to recruitment, funding, anaesthesia or blinding.
  
  
  METHODS
  Systematic review.
  
  
  METHODS
  The analysis involved studies published between 1959 and 2014 that were identified during an earlier systematic review of benefits and harms of placebo-controlled surgical trials published in 2014.
  
  
  RESULTS
  63 trials were included in the review. The main problem reported in many trials was a very slow recruitment rate, mainly due to the difficulty in finding eligible patients. Existing placebo trials were funded equally often from commercial and non-commercial sources. General anaesthesia or sedation was used in 41% of studies. Among the reviewed trials, 81% were double-blinded, and 19% were single-blinded. Across the reviewed trials, 96% (range 50-100%) of randomised patients completed the study. The withdrawal rate during the study was similar in the surgical and in the placebo groups.
  
  
  CONCLUSIONS
  This review demonstrated that placebo-controlled surgical trials are feasible, at least for procedures with a lower level of invasiveness, but also that recruitment is difficult. Many of the presumed challenges to undertaking such trials, for example, funding, anaesthesia or blinding of patients and assessors, were not reported as obstacles to completion in any of the reviewed trials.
authors.affiliation: Oxford NIHR Musculoskeletal Biomedical Research Unit, Oxford, UK Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Institute of Musculoskeletal Sciences, University of Oxford, Oxford, UK.
authors.forename: Karolina
authors.initials: K
authors.lastname: Wartolowska
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Institute of Musculoskeletal Sciences, University of Oxford, Oxford, UK Centre for Statistics in Medicine, Oxford, UK.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Collins
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Institute of Musculoskeletal Sciences, University of Oxford, Oxford, UK Centre for Statistics in Medicine, Oxford, UK.
authors.forename: Sally
authors.initials: S
authors.lastname: Hopewell
authors.affiliation: Oxford NIHR Musculoskeletal Biomedical Research Unit, Oxford, UK Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Institute of Musculoskeletal Sciences, University of Oxford, Oxford, UK MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton General Hospital, Southampton, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Judge
authors.affiliation: Oxford NIHR Musculoskeletal Biomedical Research Unit, Oxford, UK Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Institute of Musculoskeletal Sciences, University of Oxford, Oxford, UK.
authors.forename: Benjamin J F
authors.initials: BJ
authors.lastname: Dean
authors.affiliation: Oxford NIHR Musculoskeletal Biomedical Research Unit, Oxford, UK Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Institute of Musculoskeletal Sciences, University of Oxford, Oxford, UK.
authors.forename: Ines
authors.initials: I
authors.lastname: Rombach
authors.affiliation: Oxford NIHR Musculoskeletal Biomedical Research Unit, Oxford, UK Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Institute of Musculoskeletal Sciences, University of Oxford, Oxford, UK Royal College of Surgeons of England Clinical Trials Unit, Botnar Institute of Musculoskeletal Sciences, Oxford, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Beard
authors.affiliation: Oxford NIHR Musculoskeletal Biomedical Research Unit, Oxford, UK Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Botnar Institute of Musculoskeletal Sciences, University of Oxford, Oxford, UK Royal College of Surgeons of England Clinical Trials Unit, Botnar Institute of Musculoskeletal Sciences, Oxford, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Carr
mesh_terms: D000768:Anesthesia, General; D005240:Feasibility Studies; D006801:Humans; D010919:Placebos; D016032:Randomized Controlled Trials as Topic; D013514:Surgical Procedures, Operative
chemical_list: D010919:Placebos
keywords: Placebos; Randomised Controlled Trials; SURGERY