title: Validation of a portable monitor for the diagnosis of obstructive sleep apnea in morbidly obese patients.
abstract: OBJECTIVE
  We aimed to validate the diagnostic accuracy and night-to-night variability of a simple 3-channel (type IV monitor) portable sleep monitor, ApneaLink (AL), in a population of morbidly obese subjects.
  
  
  METHODS
  Cross-sectional validation and diagnostic accuracy study.
  
  
  METHODS
  Public tertiary care obesity center in Norway.
  
  
  METHODS
  A total of 105 (67 females) treatment seeking morbidly obese subjects were included, mean (SD) age 44.3 (11.4) years and BMI 43.6 (5.6) kg/m2.
  
  
  METHODS
  The patients underwent two successive nights of recordings; the first night with the AL only, and the following night with both the reference instrument Embletta (E), a type III portable somnograph, and the AL.
  
  
  RESULTS
  Main outcomes were diagnostic accuracy of AL as assessed by sensitivity, specificity and area under ROC curves, and level of agreement between AL and E. AL had high diagnostic accuracy at all levels of OSA, and the Bland-Altman plots showed good agreement between AL and E. The sensitivity and specificity of the instrument were 93% and 71% at the AHI cutoff 5 events/h, and 94% and 94% at the AHI cutoff 15, respectively. The night-to-night variability was low.
  
  
  CONCLUSIONS
  Our results indicate that a simple 3-channel portable sleep monitor (ApneaLink) has a high diagnostic accuracy in diagnosing OSA in morbidly obese treatment seeking patients. Accordingly, this and similar instruments might help non-specialists to diagnose OSA in morbidly obese patients, and, importantly, help non-specialists to refer patients who need specific treatment to specialist without unnecessary delay.
authors.affiliation: Morbid Obesity Center, Department of Medicine, Vestfold Hospital Trust, Tønsberg, Norway ; Department of Otolaryngology - Head and Neck Surgery, Vestfold Hospital Trust, Tønsberg, Norway ; Institute of Clinical Medicine, University of Oslo, Norway.
authors.forename: Jan Magnus
authors.initials: JM
authors.lastname: Fredheim
authors.affiliation: Morbid Obesity Center, Department of Medicine, Vestfold Hospital Trust, Tønsberg, Norway ; Department of Biostatistics, Institute of Basic Medical Sciences, University of Oslo, Norway.
authors.forename: J
authors.initials: J
authors.lastname: Røislien
authors.affiliation: Morbid Obesity Center, Department of Medicine, Vestfold Hospital Trust, Tønsberg, Norway ; Institute of Clinical Medicine, University of Oslo, Norway.
authors.forename: J
authors.initials: J
authors.lastname: Hjelmesæth
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods*; D009664:Norway; D009767:Obesity, Morbid / Q000150:complications*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000175:diagnosis*
keywords: obstructive sleep apnea; portable somnograph; validation