title: Comparison of positional therapy versus continuous positive airway pressure in patients with positional obstructive sleep apnea: a meta-analysis of randomized trials.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA), caused by the obstruction of the upper airway, is the most common type of sleep apnea. Continuous positive airway pressure (CPAP) and positional therapy have been shown to be effective to improve positional OSA.
  
  
  OBJECTIVE
  To compare the effectiveness of positional therapy versus CPAP on positional OSA.
  
  
  METHODS
  Prospective randomized trials were systematically searched from the OVID databases. The trials comparing positional therapy versus CPAP in patients with positional OSA were included. Apnea-hypopnea index (AHI), mean oxygen saturation level, arousal index, sleep efficiency, and sleep time were the outcomes of this meta-analysis.
  
  
  RESULTS
  Three crossover trials were identified from Canada, New Zealand, and United States from 1999 to 2010. A total of 71 patients were randomly assigned to receive CPAP or positional therapy and the mean age of patients was 51 y. Positional therapy showed higher AHI (mean difference, MD: 4.28, 95% CI: 0.72-7.83) and lower oxygen saturation level (MD: -1.04, 95% CI: -1.63 to -0.46) than CPAP. It showed no distinct advantage over CPAP in terms of arousal index, sleep efficiency, and total sleep time, but CPAP reduced sleep time in the supine position.
  
  
  CONCLUSIONS
  CPAP is superior to positional therapy in reducing the severity of sleep apnea and increasing the oxygen saturation level in patients with positional OSA.
authors.affiliation: Department of Otorhinolaryngology, Head & Neck Surgery, United Christian Hospital, Hong Kong; School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Stanley C N
authors.initials: SC
authors.lastname: Ha
authors.affiliation: School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Hoyee W
authors.initials: HW
authors.lastname: Hirai
authors.affiliation: Hong Kong Branch of the Chinese Cochrane Centre, The Chinese University of Hong Kong, Hong Kong; School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong. Electronic address: kelvin.tsoi@gmail.com.
authors.forename: Kelvin K F
authors.initials: KK
authors.lastname: Tsoi
mesh_terms: D045422:Continuous Positive Airway Pressure; D006801:Humans; D011187:Posture / Q000502:physiology*; D016684:Prone Position / Q000502:physiology; D016032:Randomized Controlled Trials as Topic; D020181:Sleep Apnea, Obstructive / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D016683:Supine Position / Q000502:physiology
keywords: Continuous positive airway pressure; Obstructive sleep apnea; Positional therapy