title: Evaluation of sham-CPAP as a placebo in CPAP intervention studies.
abstract: OBJECTIVE
  To evaluate the use of sham-continuous positive airway pressure (CPAP) treatment as a placebo intervention.
  
  
  METHODS
  Analysis of polysomnograms performed in fixed order without sham-CPAP and on the first night of the sham-CPAP intervention in participants in the CPAP Apnea Trial North American Program (CATNAP), a randomized, placebo controlled trial evaluating the effects of CPAP treatment on daytime function in adults with newly diagnosed mild to moderate obstructive sleep apnea (apnea hypopnea index (AHI) 5-30).
  
  
  METHODS
  The first 104 CATNAP participants randomized to the sham-CPAP intervention arm.
  
  
  RESULTS
  Compared to the polysomnographic measures without sham-CPAP, the study on the first night with sham-CPAP had statistically significant differences that suggested a decrease in sleep quality: decreased sleep efficiency, increased arousal index, increased time in stage 1 NREM sleep, and prolonged latency to REM sleep. However, all of these differences had a relatively small effect size. Compared to the polysomnogram without sham-CPAP, the number of hypopneas on the sham-CPAP polysomnogram was significantly increased and the number of apneas significantly decreased. Relatively minor differences in AHI with and without sham-CPAP were present and were dependent on the criteria used to score hypopneas.
  
  
  CONCLUSIONS
  Comparison of polysomnograms with and without sham-CPAP revealed differences that, although statistically significant, were small in magnitude and had relatively low effect sizes suggesting minimal clinical significance. The results support the use of sham-CPAP as a placebo intervention in trials evaluating the effects of CPAP treatment in patients with obstructive sleep apnea.
  
  
  BACKGROUND
  This paper was a secondary analysis of clinical trial data. CATNAP: CPAP Apnea Trial North American Program, the trial from which the data were obtained, is registered with clinicaltrial.gov. Registration #NCT00089752.
authors.affiliation: University of Utah College of Nursing and School of Medicine, Salt Lake City, UT, USA.
authors.forename: George W
authors.initials: GW
authors.lastname: Rodway
authors.forename: Terri E
authors.initials: TE
authors.lastname: Weaver
authors.forename: Cristina
authors.initials: C
authors.lastname: Mancini
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Cater
authors.forename: Greg
authors.initials: G
authors.lastname: Maislin
authors.forename: Bethany
authors.initials: B
authors.lastname: Staley
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Ferguson
authors.forename: Charles F P
authors.initials: CF
authors.lastname: George
authors.forename: David A
authors.initials: DA
authors.lastname: Schulman
authors.forename: Harly
authors.initials: H
authors.lastname: Greenberg
authors.forename: David M
authors.initials: DM
authors.lastname: Rapoport
authors.forename: Joyce A
authors.initials: JA
authors.lastname: Walsleben
authors.forename: Teofilo
authors.initials: T
authors.lastname: Lee-Chiong
authors.forename: Samuel T
authors.initials: ST
authors.lastname: Kuna
mesh_terms: D000328:Adult; D000368:Aged; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000628:therapy*; D012894:Sleep Stages
chemical_list: D010919:Placebos