HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:
Guest Access | Sign In via User Name/Password

This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (12) Citing Articles via Google Scholar Google Scholar Articles by Magalang, U. J. Articles by Grant, B. J. B. Search for Related Content PubMed PubMed Citation Articles by Magalang, U. J. Articles by Grant, B. J. B.

Prediction of the Apnea-Hypopnea Index From Overnight Pulse Oximetry^*

^* From the Division of Pulmonary, Critical Care, and Sleep Medicine (Drs. Magalang, Draw, and El-Solh), Department of Medicine (Dr. Veeramachaneni); Department of Social and Preventive Medicine (Dr. Dmochowski), University at Buffalo; and Veterans Affairs Medical Center (Drs. Mador and Grant), Buffalo, NY.

Correspondence to: Brydon J. B. Grant, MD, FCCP, Veterans Affairs Medical Center (111-S), 3495 Bailey Ave, Buffalo, NY 14215; e-mail: grant{at}buffalo.edu

Study objectives: To compare the relative usefulness of the different indexes derived from pulse oximetry in the diagnosis of obstructive sleep apnea (OSA), and to determine if a combination of these indexes improves the prediction of the apnea-hypopnea index (AHI) measured by polysomnography.

Design: Prediction model developed from 224 patients, validated prospectively in 101 patients from the same center (group 1) and in 191 patients from a different sleep center (group 2).

Setting: Two independent sleep clinics run by university sleep specialists.

Participants: Patients who underwent polysomnography for suspicion of OSA.

Interventions: The following indexes were calculated from pulse oximetry recordings performed simultaneously during polysomnography: (1) index, the average of the absolute differences of oxygen saturation between successive 12-s intervals; (2) desaturation events per hour to 2%, 3%, and 4% levels; and (3) cumulative time spent below 90%, 88%, 86%, 84%, 82%, and 80% saturation.

Measurements and results: The best predictor was the index, although desaturation events provided similar levels of diagnostic accuracy. An aggregation of multivariate models using combination of indexes reduced the prediction error (r² = 0.70) significantly (p < 0.05) compared to using the index alone (r² = 0.60). The proportion of subjects from the validation groups within 95% confidence interval (CI) of the derivation group was 90% (95% CI, 83 to 95%) and 91% (95% CI, 86 to 95%) for groups 1 and 2, respectively. The overall likelihood ratios for the aggregated model in all patient groups were 4.2 (95% CI, 3.3 to 15.3), 3.4 (95% CI, 2.7 to 4.3), 3.0 (95% CI, 2.2 to 4.1), and 6.7 (95% CI, 4.9 to 9.2) for normal (AHI < 5/h), mild (AHI 5 to < 15/h), moderate (AHI 15 to < 30/h), and severe (AHI 30/h) disease, respectively.

Conclusions: The index and oxygen desaturation indexes provided similar levels of diagnostic accuracy. The combination of indexes improved the precision of the predicted AHI and may offer a potentially simpler alternative to polysomnography.

Key Words: bootstrap aggregation • clinical prediction rules • multivariate adaptive regression splines • overnight polysomnography • pulse oximetry • sleep apnea syndrome

This article has been cited by other articles:

				D. Hwang, N. Shakir, B. Limann, C. Sison, S. Kalra, L. Shulman, A. d. C. Souza, and H. Greenberg Association of Sleep-Disordered Breathing With Postoperative Complications Chest, May 1, 2008; 133(5): 1128 - 1134. [Abstract] [Full Text] [PDF]

				R. Ramsey, R. Mehra, and K. P. Strohl Variations in Physician Interpretation of Overnight Pulse Oximetry Monitoring Chest, September 1, 2007; 132(3): 852 - 859. [Abstract] [Full Text] [PDF]

				C.-C. Hua and C.-C. Yu Smoothed Periodogram of Oxyhemoglobin Saturation by Pulse Oximetry in Sleep Apnea Syndrome: An Automated Analysis Chest, March 1, 2007; 131(3): 750 - 757. [Abstract] [Full Text] [PDF]