title: The role of single-channel nasal airflow pressure transducer in the diagnosis of OSA in the sleep laboratory.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is a common but underdiagnosed disorder. There is a need for validated simpler modalities such as single-channel monitors to assist diagnosis of OSA.
  
  
  OBJECTIVE
  To assess data sufficiency, agreement, and diagnostic accuracy of nasal airflow measured by a single-channel pressure transducer device (Flow Wizard, DiagnoseIT, Sydney, Australia) compared to attended full polysomnography (PSG) on the same night for OSA diagnosis.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Subjects with possible OSA referred to the sleep laboratory for PSG were eligible.
  
  
  METHODS
  Nasal airflow was measured by a pressure transducer in the laboratory concurrently with PSG.
  
  
  RESULTS
  Of 226 eligible subjects who consented, 221 (97.8%; 151 males, 70 females) completed the protocol. With nasal airflow measurement, 5.3% of subjects had insufficient data, compared with 2.2% on PSG. The mean difference between PSG AHI and NF RDI was -6.2 events/h with limits of agreement (+/- 2 standard deviation [SD]) of 17.0 events/hr. The accuracy of the Flow Wizard for diagnosing severe OSA (PSG AHI > 30) was very good (area under the ROC curve [AUC] 0.96; 95% confidence interval [CI] 0.92 to 0.99) and for diagnosing OSA (PSG AHI > 5) was good (AUC, 0.84; 95% CI, 0.77 to 0.90). There was no difference in the rate of data insufficiency and accuracy between males and females.
  
  
  CONCLUSIONS
  Nasal flow measured by a nasal pressure transducer has a low rate of data insufficiency, good agreement, and high accuracy compared to PSG for diagnosing OSA in the monitored sleep laboratory setting.
authors: National Health Medical Research Council Centre for Clinical Research Excellence in Respiratory and Sleep Medicine, Australia. lydiamr@woolcock.org.au
authors: Lydia Makarie
authors: LM
authors: Rofail
authors: Keith K H
authors: KK
authors: Wong
authors: Gunnar
authors: G
authors: Unger
authors: Guy B
authors: GB
authors: Marks
authors: Ronald R
authors: RR
authors: Grunstein
mesh_terms: D000328:Adult; D003362:Cost-Benefit Analysis; D003430:Cross-Sectional Studies; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000191:economics / Q000295:instrumentation*; D025363:Rhinomanometry / Q000191:economics / Q000295:instrumentation*; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000191:economics; D014160:Transducers, Pressure