Usefulness of sleep events detection using a wrist worn peripheral arterial tone signal device (WatchPAT™) in a population at low risk of obstructive sleep apnea

Due to the high prevalence of obstructive sleep apnea (OSA), it is recommended to use in-laboratory polysomnography (PSG) or a home sleep apnea test (HSAT) in uncomplicated adult subjects at high risk of OSA. The aims of the present study were to compare a HSAT device, a wrist worn peripheral arterial tone signal device (WatchPAT™-200 [WP]) with PSG and respiratory polygraphy (RP) in a low-risk population of OSA. A total of 47 adult subjects at low risk of OSA were simultaneously examined with the three different approaches in a single night. The sleep studies were scored independently and in a blinded fashion, then the results and the parameters (Respiratory Disturbance Index, apnea–hypopnea index [AHI] and oxygen desaturation index of 3%) were compared with several statistical analyses. The agreement between the sleep tools and correlation for the assessed parameters were analysed and compared with Bland and Altman plots and Pearson’s coefficient (WP versus PSG, r = 0.86). For the severity of OSA ranked according to PSG, the Cohen’s k was 0.60 and 0.82 for WP and RP, respectively. Specificity was higher for RP compared to WP for identifying the presence of OSA (AHIPSG cut-off ≥5 events/hr: 0.85 versus 0.73), while was quite similar in identifying patients who were more likely to be treated (AHIPSG cut-off ≥15 events/hr: 0.94 versus 0.96). Assessing the costs and the simplicity of the examination, the results of our present study demonstrate the usefulness of WP compared to PSG, especially in screening and follow-up for the ability to exclude subjects from treatment with continuous positive airway pressure (AHI <15 events/hr) in a population with a low pre-test risk of moderate-to-severe OSA.