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.
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.
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.
The WP100 seems accurate for classification of obstructive sleep apnea syndrome severity up to a WP100-
measured 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.