title: Utility of Acoustic Pharyngometry for the Diagnosis of Obstructive Sleep Apnea.
abstract: Owing to resource limitations, the testing of patients for obstructive sleep apnea (OSA) is often delayed. There is a need to accurately triage and expedite testing in those with a high pretest probability of OSA. Acoustic pharyngometry is a simple, noninvasive technique used to assess the upper airway cross-sectional area (UA-XSA), which is known to be reduced in those with OSA.
  
  
  
  To determine the discriminative ability and predictive value of UA-XSA measurements by acoustic pharyngometry for OSA.
  
  
  
  We conducted a cross-sectional study with a clinical cohort of consecutive adults with suspected OSA who had undergone both polysomnography and acoustic pharyngometry. OSA was defined as an apnea-hypopnea index greater than or equal to 5. Multivariable logistic regression analyses and receiver operating characteristic curves were used.
  
  
  
  The cohort included 576 subjects, 87% of whom had OSA and 64% of whom were men. The subjects' median body mass index (BMI) was 30.3 kg/m2, and their median age was 57 years. The median UA-XSA at FRC when sitting was significantly smaller in those with OSA compared with those without OSA (3.3 cm2[interquartile range, 2.7-3.8] vs. 3.7 cm2[interquartile range, of 2.9-4.2]). When the analysis was controlled for age, sex, BMI, and comorbidities, the odds of OSA increased for every 1-cm2decrease in the mean UA-XSA FRC when sitting (odds ratio, 1.62; 95% confidence interval, 1.23-2.13). The mean UA-XSA provided fair discrimination for OSA (area under the curve, 0.60). A cutoff value of 3.75 cm2, the point with the best sum of sensitivity and specificity, had sensitivity of 73% and specificity of 46%. The magnitude of the incremental discriminative value of UA-XSA over clinical variables (age, sex, BMI, and comorbidities) was small and nonsignificant (P = 0.5).
  
  
  
  The mean UA-XSA at FRC when sitting or supine provided no further significant advantage over clinical variables for the discernment of OSA.
authors.affiliation: 1 Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.|2 Sunnybrook Research Institute, Toronto, Ontario, Canada.|3 University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tetyana
authors.identifier: 0000-0002-5301-1796
authors.initials: T
authors.lastname: Kendzerska
authors.affiliation: 4 Royal College of Physicians and Surgeons Ireland; and.|5 Centre for Sleep Health and Research, Toronto General Hospital University Health Network, Toronto, Ontario, Canada.
authors.forename: Monica
authors.initials: M
authors.lastname: Grewal
authors.affiliation: 3 University of Toronto, Toronto, Ontario, Canada.|5 Centre for Sleep Health and Research, Toronto General Hospital University Health Network, Toronto, Ontario, Canada.
authors.forename: Clodagh M
authors.identifier: 0000-0002-2372-965X
authors.initials: CM
authors.lastname: Ryan
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002170:Canada; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010614:Pharynx / Q000503:physiopathology*; D017286:Polysomnography; D012372:ROC Curve; D012137:Respiratory System / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis*
keywords: acoustic pharyngometry; obstructive sleep apnea; screening