The Portable Device “Watch PAT” as a Diagnostic Method of Sleep-Disordered Breathing

Abstract

Objectives:

1) Evaluate the accuracy of Watch PAT in diagnosing sleep-disordered breathing (SDB). 2) Compare the results of Watch PAT and polysomnography (PSG).

Methods:

Prospective study performed between February and December 2012. Thirty patients with suggestive complaints of respiratory sleep disorder underwent Watch PAT and polysomnography simultaneously.

Results:

Twenty men and ten women underwent the sleep studies. Mean age was 42.8 ± 12.32 years. There was a trend that the apnea / hypopnea index (AHI) of Watch PAT was significantly higher than that of PSG (p<0.001); however the values of AHI of both sleep studies were significantly correlated (r = 0.762). There was also a high correlation between the values of the following variables: minimum oxygen saturation (r = 0.842, p<0.001), oxygen saturation <90% (r = 0.799, p <0.001), and mean heart frequency (r = 0.951, p <0.001). The analysis which used ROC curve to test the diagnostic efficiency of Watch PAT concluded that the area under the curve could reach 0.727 if the threshold of 12 events/hour was used as the cut-off point in this study with a sensitivity of 96.2% and a specificity of 60%. When analyzing the severe cases of obstructive sleep apnea (OSA) (AHI ≥ 30 events/hour), the area under the curve was 0.846 with a sensitivity of 77.8% and a specificity of 86.4%.

Conclusions:

Watch PAT tends to overestimate the AHI when compared with PSG, especially for mild OSA. The Watch PAT is an alternative method that is reliable and highly sensitive for the diagnosis of SDB.