title: Comparison of the indices of oxyhemoglobin saturation by pulse oximetry in obstructive sleep apnea hypopnea syndrome.
abstract: OBJECTIVE
  To comprehensively evaluate the ability and reliability of the representative previously proposed oxyhemoglobin indexes derived automatically for predicting the severity of obstructive sleep apnea hypopnea syndrome (OSAHS).
  
  
  METHODS
  Patients with a diagnosis of OSAHS by standard polysomnography were recruited from China Medical University Hospital Centre. There were 257 patients in the learning set and 279 patients in the validation set. The presence of OSAHS was defined as apnea-hypopnea index (AHI) > 5/h. Three kinds of oxyhemoglobin indexes, including the oxyhemoglobin desaturation index (ODI), time-domain index, and frequency-domain index, were used. Degrees of severity were AHI > 15/h and AHI > 30/h, representing moderate and severe OSAHS. A total of 28 oxyhemoglobin indexes were tested in our study.
  
  
  RESULTS
  Among the three kinds of indexes, ODI had a better diagnostic performance than the time-domain and frequency-domain indexes, with the results coincident in the validation set and learning set. For predicting the severity of OSAHS with AHI > 15/h or > 30/h, the ODI clinically had the higher correlation with AHI than time-domain and frequency-domain indexes, with sensitivity/specificity achieving 84.0%/84.3% in AHI > 15/h and 87.8%/96.6% in AHI > 30/h, respectively.
  
  
  CONCLUSIONS
  Based on the smaller SEE of the AHI, the ODI had a significantly smaller SEE than the time-domain and frequency-domain indexes. The ODI index provided a high level of diagnostic sensitivity and specificity at different degrees of OSAHS severity.
authors.affiliation: Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung.
authors.forename: Chen-Liang
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung.
authors.forename: Chinson
authors.initials: C
authors.lastname: Yeh
authors.affiliation: Sleep Medicine Center, Taichung, Taiwan.
authors.forename: Chen-Wen
authors.initials: CW
authors.lastname: Yen
authors.affiliation: Department of Internal Medicine, and Division of Pulmonary and Critical Care, Taichung, Taiwan.
authors.forename: Wu-Huei
authors.initials: WH
authors.lastname: Hsu
authors.affiliation: Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan. Electronic address: lungwen.hang@gmail.com.
authors.forename: Liang-Wen
authors.initials: LW
authors.lastname: Hang
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010108:Oxyhemoglobins / Q000378:metabolism*; D017286:Polysomnography; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000175:diagnosis*
chemical_list: D010108:Oxyhemoglobins