Evaluation of a Portable Monitor (Watch-PAT100) and Implications for Clinical Guidelines for the Use of Portable Monitors in Diagnosing OSAS

Objective: To evaluate, industry independently, the accuracy of the Watch-PAT100 system (WP100) [Itamar Medical; Caesarea, Israel], a portable home sleep test, compared to polysomnography, the gold standard for diagnosing obstructive sleep apnea syndrome. Methods: Prospective clinical trial. 27 patients (24 male, 3 female) were evaluated at our institution's sleep laboratory. The apnea hypopnea index and oxygen desaturation index were used to compare the 2 testing modalities. Results: Non-parametrical testing showed a Kendall's tau = 0.685 for apnea hypopnea index and 0.748 for oxygen desaturation index. We found that the WP100 system overestimated the severity of obstructive sleep apnea syndrome in 33% when compared to polysomnography. The test-agreement was in particular poor when the WP100 indicated moderate to severe obstructive sleep apnea syndrome. Conclusion: The WP100 seems accurate for classification of obstructive sleep apnea syndrome severity up to a WP100measured apnea hypopnea index of 15. In patients with an apnea hypopnea index of more than 15 as measured with the WP100, additional polysomnography should be performed.