Peripheral arterial tonometry (PAT) based technology represents a validated portable monitoring modality for diagnosis of obstructive sleep apnea (OSA). We assessed the diagnostic accuracy of PAT-based technology in a large point-of-care cohort of patients studied with concurrent polysomnography (PSG).
During study enrollment, all participants suspected to have OSA and tested by in-laboratory PSG underwent concurrent PAT device recordings.
Five hundred concomitant PSG and WatchPat tests were analyzed. Median (interquartile range, IQR) PSG AHI was 18 (8-37), while PAT AHI (pAHI) was 25 (12-46). Average bias was +4 events/hour. Diagnostic concordance was found in 42%, 41% and 83% of mild, moderate and severe OSA, respectively (accuracy: 53%). Among those with PAT diagnoses of moderate or severe OSA, 5% did not have OSA and 19% had mild OSA; in those with mild OSA, PSG showed moderate or severe disease in 20%, and no OSA in 30% of cases (accuracy: 69%). On average, using a 3% desaturation threshold, WatchPat overestimated disease prevalence and severity (mean +4 events/hour), while the 4% threshold underestimated it (by -6 events/hour).
While there was an overall tendency to overestimate the severity of OSA, significant percentage of patients had clinically relevant misclassifications. As such, we recommend that patients without OSA or with mild disease by PAT undergo repeat in-laboratory PSG. Optimized clinical pathways are urgently needed to minimize therapeutic decisions instituted in the presence of diagnostic uncertainty.

© 2020 American Academy of Sleep Medicine.