title: Comparison of in-laboratory and home diagnosis of sleep apnea using a cordless portable acoustic device.
abstract: Sleep apnea (SA) is a common, serious, but underdiagnosed condition. There is a need for more accessible and economic means of diagnosing SA in the home. The aim of this study was to test the validity of a cordless acoustic portable device (BresoDx™) for home diagnosis of SA compared with standard polysomnography (PSG).
  
  
  
  A total of 135 subjects underwent full overnight PSG and simultaneous recording of breath sounds by BresoDx in the sleep laboratory. Acoustic data extracted from BresoDx were analyzed using validated computer acoustic algorithms. The PSG-derived apnea-hypopnea index (AHI-p) and the acoustic AHI (AHI-a) were calculated and compared. A subset of 100 subjects used the device in a subsequent night in their home from which home AHI (AHI-h) was determined.
  
  
  
  The correlation between AHI-a and simultaneous AHI-p was 95.2% and diagnostic accuracy of BresoDx ranged between 88.9% and 93.3% around AHI cutoffs of 5-15. In the home, AHI-h did not differ significantly from AHI-p (p = 0.60). Using an AHI-p cutoff ≥ 10 BresoDx's accuracy was 81%. Of the 100 subjects, 81 (81%) had low inter-night variability measured by a difference between home AHI-h and PSG AHI-p < 10 event/h, while 19% had higher inter-night variability.
  
  
  
  AHI determined using BresoDx was in excellent agreement with simultaneous AHI-p. The majority of patients had a consistent AHI in their subsequent home study with very good overall diagnostic accuracy. We conclude that BresoDx is a reliable device for diagnosing SA that can be used by subjects, unattended in their own homes.
authors.affiliation: Sleep Research Laboratory and Home, Community and Institutional Environments Team, Toronto Rehabilitation Institute, University Health Network, Toronto Rehabilitation Institute, Toronto, ON, Canada. Electronic address: hisham.alshaer@uhn.ca.
authors.forename: Hisham
authors.initials: H
authors.lastname: Alshaer
authors.affiliation: Toronto Rehabilitation Institute, University Health Network Toronto Rehabilitation Institute, Toronto, ON, Canada.
authors.forename: Geoff R
authors.initials: GR
authors.lastname: Fernie
authors.affiliation: Sleep Research Laboratory, Toronto Rehabilitation Institute, University Health Network Toronto Rehabilitation Institute, Department of Occupational Science and Occupational therapy, Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Department of Occupational Science and Occupational therapy, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Wen-Hou
authors.initials: WH
authors.lastname: Tseng
authors.affiliation: Sleep Research Laboratory and Home, Community and Institutional Environments Team, Toronto Rehabilitation Institute, University Health Network, Toronto Rehabilitation Institute, Toronto, ON, Canada; Sleep Research Laboratories of the Toronto Rehabilitation Institute and Toronto General Hospital, University Health Network; Centre for Sleep Medicine and Circadian Biology of the University of Toronto, Toronto, ON, Canada.
authors.forename: T Douglas
authors.initials: TD
authors.lastname: Bradley
mesh_terms: D000162:Acoustics; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation; D017286:Polysomnography / Q000295:instrumentation*; D015203:Reproducibility of Results; D012891:Sleep Apnea Syndromes / Q000175:diagnosis*
keywords: Acoustic; Cordless portable device; Home diagnosis; Sleep apnea