title: Factors predictive of obstructive sleep apnea in patients undergoing pre-operative evaluation for bariatric surgery and referred to a sleep laboratory for polysomnography.
abstract: OBJECTIVE
  To identify the main predictive factors for obtaining a diagnosis of obstructive sleep apnea (OSA) in patients awaiting bariatric surgery.
  
  
  METHODS
  Retrospective study of consecutive patients undergoing pre-operative evaluation for bariatric surgery and referred for in-laboratory polysomnography. Eight variables were evaluated: sex, age, neck circumference (NC), BMI, Epworth Sleepiness Scale (ESS) score, snoring, observed apnea, and hypertension. We employed ROC curve analysis to determine the best cut-off value for each variable and multiple linear regression to identify independent predictors of OSA severity.
  
  
  RESULTS
  We evaluated 1,089 patients, of whom 781 (71.7%) were female. The overall prevalence of OSA-defined as an apnea/hypopnea index (AHI) ≥ 5.0 events/h-was 74.8%. The best cut-off values for NC, BMI, age, and ESS score were 42 cm, 42 kg/m2, 37 years, and 10 points, respectively. All eight variables were found to be independent predictors of a diagnosis of OSA in general, and all but one were found to be independent predictors of a diagnosis of moderate/severe OSA (AHI ≥ 15.0 events/h), the exception being hypertension. We devised a 6-item model, designated the NO-OSAS model(NC, Obesity, Observed apnea, Snoring, Age, and Sex), with a cut-off value of ≥ 3 for identifying high-risk patients. For a diagnosis of moderate/severe OSA, the model showed 70.8% accuracy, 82.8% sensitivity, and 57.9% specificity.
  
  
  CONCLUSIONS
  In our sample of patients awaiting bariatric surgery, there was a high prevalence of OSA. At a cut-off value of ≥ 3, the proposed 6-item model showed good accuracy for a diagnosis of moderate/severe OSA.
authors.affiliation: Centro Médico BarraShopping, Rio de Janeiro, Brasil.
authors.forename: Ricardo Luiz de Menezes
authors.initials: RL
authors.lastname: Duarte
authors.affiliation: Centro Médico BarraShopping, Rio de Janeiro, Brasil.
authors.forename: Flavio José
authors.initials: FJ
authors.lastname: Magalhães-da-Silveira
mesh_terms: D000328:Adult; D000367:Age Factors; D050110:Bariatric Surgery; D015992:Body Mass Index; D001938:Brazil / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology; D017286:Polysomnography; D011300:Preoperative Care; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*