title: Effects of perceived treatment on quality of life and medical outcomes in a double-blind placebo surgery trial.
abstract: BACKGROUND
  This study was part of a large double-blind sham surgery-controlled trial designed to determine the effectiveness of transplantation of human embryonic dopamine neurons into the brains of persons with advanced Parkinson's disease. This portion of the study investigated the quality of life (QOL) of participants during the 1 year of double-blind follow-up.
  
  
  OBJECTIVE
  To determine whether QOL improved more in the transplant group than in the sham surgery group and to investigate outcomes at 1 year based on perceived treatment (the type of surgery patients thought they received).
  
  
  METHODS
  Participants were randomly assigned to receive either the transplant or sham surgery. Reported results are from the 1-year double-blind period.
  
  
  METHODS
  Participants were recruited from across the United States and Canada. Assessment and surgery were conducted at 2 separate university medical centers.
  
  
  METHODS
  A volunteer sample of 40 persons with idiopathic Parkinson's disease participated in the transplant ("parent") study, and 30 agreed to participate in the related QOL study: 12 received the transplant and 18 received sham surgery.
  
  
  METHODS
  Interventions in the parent study were transplantation and sham brain surgery. Assessments of QOL were made at baseline and 4, 8, and 12 months after surgery.
  
  
  METHODS
  Comparison of the actual transplant and sham surgery groups and the perceived treatment groups on QOL and medical outcomes. We also investigated change over time.
  
  
  RESULTS
  There were 2 differences or changes over time in the transplant and sham surgery groups. Based on perceived treatment, or treatment patients thought they received, there were numerous differences and changes over time. In all cases, those who thought they received the transplant reported better scores. Blind ratings by medical staff showed similar results.
  
  
  CONCLUSIONS
  The placebo effect was very strong in this study, demonstrating the value of placebo-controlled surgical trials.
authors.affiliation: College of Education, University of Denver, Denver, CO 80208, USA. cmcrae@du.edu
authors.forename: Cynthia
authors.initials: C
authors.lastname: McRae
authors.forename: Eva
authors.initials: E
authors.lastname: Cherin
authors.forename: T Gayle
authors.initials: TG
authors.lastname: Yamazaki
authors.forename: Gretchen
authors.initials: G
authors.lastname: Diem
authors.forename: Alexander H
authors.initials: AH
authors.lastname: Vo
authors.forename: Dan
authors.initials: D
authors.lastname: Russell
authors.forename: J Heiner
authors.initials: JH
authors.lastname: Ellgring
authors.forename: Stanley
authors.initials: S
authors.lastname: Fahn
authors.forename: Paul
authors.initials: P
authors.lastname: Greene
authors.forename: Sandra
authors.initials: S
authors.lastname: Dillon
authors.forename: Hal
authors.initials: H
authors.lastname: Winfield
authors.forename: Kimberly B
authors.initials: KB
authors.lastname: Bjugstad
authors.forename: Curt R
authors.initials: CR
authors.lastname: Freed
mesh_terms: D000368:Aged; D016380:Brain Tissue Transplantation; D004298:Dopamine / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D016332:Fetal Tissue Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000637:transplantation*; D010300:Parkinson Disease / Q000523:psychology* / Q000628:therapy*; D010465:Perception; D015990:Placebo Effect; D010919:Placebos; D011788:Quality of Life; D016896:Treatment Outcome
chemical_list: D010919:Placebos; D004298:Dopamine