title: [Predictive value of clinical features and nocturnal oximetry for the detection of obstructive sleep apnea syndrome].
abstract: BACKGROUND
  Obstructive sleep apnea syndrome (OSA) is an important cause of morbidity and mortality in adults.
  
  
  OBJECTIVE
  To evaluate the diagnostic value of clinical features and oximetric data to screen for obstructive sleep apnea before performing polysomnograpy or respiratory polygraphy.
  
  
  METHODS
  We studied 328 consecutive adult patients referred for snoring or excessive daytime sleepiness to a sleep clinic in whom a standardized questionnaire and the Sleepiness Epworth Scale were performed and body mass index (BMI), cervical circumference (CC), and nocturnal oximetry were measured.
  
  
  RESULTS
  Fifty three percent (n = 173) had evidence of clinically significant OSA (apnea/hypopnea index (AHI) > 15 events/h). Patients with OSA were more likely to be male, obese (BMI ≥ 26 kg/m²), smokers, to have a thick neck (CC > 41 cm), and to have a significant greater prevalence of relative reported apneas and excessive daytime sleepiness, as determined by Epworth scale. Male gender (Odds ratio (OR): 4.00; 95% confidence intervals (CI): 1.59-10.0, p = 0.003), BMI ≥ 26 kg/m² (OR: 3.68; 95%CI: 1.59-8.49, p = 0.002), smoking (OR: 2.29; 95% CI: 1.17-4.47, p = 0.015), Epworth index > 13 (OR: 2.65; 95% CI: 1.35-5.23, p = 0.005) and duration of symptoms over 2 years (OR: 2.35; 95% CI: 1.20-4.58, p = 0.012) were significant independent predictors of OSA. In nocturnal oximetry, the lowest SpO2 (SpO2 min) and the length of registries below 90% (CT-90) were independent predictors of OSA and both correlated significantly with AHI (r = -0.49 and r = 0.46 respectively, p < 0.001).
  
  
  CONCLUSIONS
  No single factor was usefully predictive of obstructive sleep apnea. However, combining clinical features and oximetry data may be appropriate to detect clinically significant OSA patients.
authors.affiliation: Departamento de Enfermedades respiratorias, Pontifica Universidad de Chile, Santiago, Chile. fsaldias@med.puc.cl
authors.forename: Fernando
authors.initials: F
authors.lastname: Saldías P
authors.forename: Jorge
authors.initials: J
authors.lastname: Jorquera A
authors.forename: Orlando
authors.initials: O
authors.lastname: Díaz P
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D006970:Disorders of Excessive Somnolence / Q000453:epidemiology / Q000473:pathology*; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000473:pathology*; D010092:Oximetry; D017286:Polysomnography; D012737:Sex Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology*; D055815:Young Adult