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Sleep Disorders
Volume 2015, Article ID 293868, 11 pages
Review Article

Mathematical Equations to Predict Positive Airway Pressures for Obstructive Sleep Apnea: A Systematic Review

1Division of Otolaryngology, Sleep Surgery, and Sleep Medicine, Tripler Army Medical Center, 1 Jarrett White Road, Tripler AMC, HI 96859, USA
2Sleep Medicine Division, Department of Psychiatry and Behavioral Sciences, Stanford Hospital and Clinics, Redwood City, CA 94063, USA
3Sleep Disorders Center, University of Michigan, Ann Arbor, MI 48109, USA
4Department of Internal Medicine, Highland Hospital, Alameda Health System, Oakland, CA 94602, USA
5Department of Otorhinolaryngology/Sleep Medicine Centre, Hospital CUF, 4100-180 Porto, Portugal
6CINTESIS-Centre for Research in Health Technologies and Information Systems, University of Porto, 4200-450 Porto, Portugal

Received 4 May 2015; Revised 1 July 2015; Accepted 5 July 2015

Academic Editor: Michel M. Billiard

Copyright © 2015 Macario Camacho et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Objective. To systematically review the international literature for mathematical equations used to predict effective pressures for positive airway pressure (PAP) devices. Methods. Google Scholar, PubMed, Scopus, Embase, Web of Science, CINAHL, and The Cochrane Library were searched through June 27, 2015. The PRISMA statement was followed. There was no language limitation. Results. 709 articles were screened, fifty were downloaded, and twenty-six studies presented equations that met the inclusion and exclusion criteria. In total, there were 4,436 patients in the development phases and 3,489 patients in the validation phases. Studies performed multiple linear regressions analyses as part of the equation(s) development and included the following variables: physical characteristics, polysomnography data, behavioral characteristics, and miscellaneous characteristics, which were all predictive to a variable extent. Of the published variables, body mass index (BMI) and mean oxygen saturation are the most heavily weighted, while BMI (eighteen studies), apnea-hypopnea index (seventeen studies), and neck circumference (eleven studies) were the variables most frequently used in the mathematical equations. Ten studies were from Asian countries and sixteen were from non-Asian countries. Conclusion. This systematic review identified twenty-six unique studies reporting mathematical equations which are summarized. Overall, BMI and mean oxygen saturation are the most heavily weighted.