Validation study of WatchPat 200 for diagnosis of OSA in an Asian cohort.

To validate a wrist-worn portable device (WatchPat 200) to diagnose OSA in an Asian cohort. To evaluate its cost-effectiveness. Twenty patients with suspected OSA were recruited and had simultaneous polysomnography (PSG) and WatchPAT assessments concurrently within the hospital's sleep laboratory. The study population consisted of 18 male and 2 female patients, whose mean age was 39 (±16) years, mean BMI was 27.2 (±5.5) kg/m2, mean Epworth Sleepiness score was 8.55 (±4.8). The correlation between the AHI was assessed using Spearman's correlation coefficient and agreement was tested via the Bland Altman plot. Sensitivities and specificities were then applied to the various AHI groups. Spearman's coefficient was 0.94, which suggested that a very strong correlation between the AHI recorded by the WatchPat and the PSG. Bland-Altman plot showed good agreement with the AHI mean difference of about 4.23 with a slight tendency to overscore the AHI at the mild range of OSA and underscore the range at the severe end of OSA. The WatchPat showed 100% sensitivity when compared to PSG for mild OSA and is thus a good screening test for the undiagnosed general population. Furthermore, it also showed 100% specificity when compared to PSG for severe OSA suggesting that it is a good diagnostic test for people with a high suspicion of OSA. This facilitates a timelier diagnosis and a more economical approach with potential cost savings of up to $900 per patient.