title: Accurate position monitoring and improved supine-dependent obstructive sleep apnea with a new position recording and supine avoidance device.
abstract: OBJECTIVE
  Approximately 30% of obstructive sleep apnea (OSA) patients have supine-predominant OSA, and simply avoiding supine sleep should normalise respiratory disturbance event rates. However, traditional supine-avoidance therapies are inherently uncomfortable, and treatment adherence is poor and difficult to monitor objectively. This study evaluated the efficacy of a novel, potentially more acceptable position monitor and supine-avoidance device for managing supine-predominant OSA and snoring.
  
  
  METHODS
  In-laboratory evaluation of position recording accuracy versus video recordings (validation study), and randomized controlled crossover trial of active versus inactive supine-avoidance therapy in the home setting (efficacy study).
  
  
  METHODS
  17 patients undergoing in-laboratory sleep studies (validation) and 15 patients with supine-predominant OSA (efficacy).
  
  
  METHODS
  EFFICACY STUDY: 1 week of inactive and 1 week of active treatment in randomized order, separated by 1 week.
  
  
  RESULTS
  Agreement between 30-sec epoch-based posture classifications from device versus video records was high (median κ 0.95, interquartile range: 0.88-1.00), and there was good supine time agreement (bias 0.3%, 95%CI: -4.0% to 4.6%). In the efficacy study, apnea-hypopnea index (AHI) and snoring frequency were measured in-home using a nasal pressure and microphone based system during inactive and active treatment weeks. The position monitoring and supine alarm device markedly inhibited supine time (mean ± SEM 19.3% ± 4.3% to 0.4% ± 0.3%, p < 0.001) and reduced AHI (25.0 ± 1.7 to 13.7 ± 1.1 events/h, p = 0.030) but not snoring frequency.
  
  
  CONCLUSIONS
  This new position monitoring and supine alarm device records sleep position accurately and improves OSA but not snoring in patients with supine-predominant OSA.
authors: Adelaide Institute for Sleep Health, Repatriation General Hospital, Daw Park, Adelaide, South Australia.
authors: James J
authors: JJ
authors: Bignold
authors: Jeremy D
authors: JD
authors: Mercer
authors: Nick A
authors: NA
authors: Antic
authors: R Doug
authors: RD
authors: McEvoy
authors: Peter G
authors: PG
authors: Catcheside
mesh_terms: D000328:Adult; D000367:Age Factors; D056902:Clinical Alarms / Q000706:statistics & numerical data*; D016001:Confidence Intervals; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D056888:Patient Positioning / Q000295:instrumentation*; D017286:Polysomnography / Q000379:methods; D012016:Reference Values; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000517:prevention & control* / Q000628:therapy*; D012913:Snoring / Q000517:prevention & control / Q000628:therapy; D013021:South Australia; D016683:Supine Position / Q000502:physiology; D016896:Treatment Outcome; D014741:Video Recording