Abstract
STUDY OBJECTIVES: During positive airway pressure (PAP) therapy for sleep apnea syndromes, the machine-detected respiratory event index (REI(FLOW)) is an important method for clinicians to evaluate the beneficial effects of PAP. There are concerns about the accuracy of this detection, which also confounds a related question, How common and severe are residual events on PAP? METHODS: Patients with obstructive sleep apnea who underwent a split-night polysomnography were recruited prospectively. Those treated with PAP and tracked by the EncoreAnywhere system (Philips Respironics, Murrysville, PA) were analyzed. Those who stopped PAP within 1 month were excluded from this analysis. Compliance, therapy data, and waveform data were analyzed. Machine-detected vs manually scored events were compared at the first, third, sixth, and 12th month from PAP initiation. Logistic regression was used to determine factors associated with a high REI(FLOW) difference. RESULTS: One hundred and seventy-nine patients with a mean age 59.06 ± 13.97 years, median body mass index of 33.60 (29.75-38.75) kg/m(2), and median baseline apnea-hypopnea index of 46.30 (31.50-65.90) events/h were included. The difference between the machine-detected REI(FLOW) and manually scored REI(FLOW) was 10.72 ± 8.43 events/h in the first month and remained stable for up to 12 months. Male sex and large leak ≥ 1.5% were more frequent in patients who had an REI(FLOW) difference of ≥ 5 events/h of use. A titration arousal index ≥ 15 events/h of sleep, and higher ratio of unstable to stable breathing were also associated with an REI(FLOW) difference ≥ 5 events/h of use. CONCLUSIONS: There is a substantial and sustained difference between manual and automated event estimates during PAP therapy, and some associated factors were identified. CITATION: Ni Y-N, Thomas RJ. A longitudinal study of the accuracy of positive airway pressure therapy machine-detected apnea-hypopnea events. J Clin Sleep Med. 2022;18(4):1121-1134.