Validation of an Overnight Wireless High-Resolution Oximeter plus Cloud-Based Algorithm for the Diagnosis of Obstructive Sleep Apnea

Abstract

Obstructive sleep apnea (OSA) is a common but largely underdiagnosed condition. This study aimed to test the hypothesis that the oxygen desaturation index (ODI) obtained using a wireless high-resolution oximeter with a built-in accelerometer linked to a smartphone with automated cloud analysis, Overnight Digital Monitoring (ODM), is a reliable method for the diagnosis of OSA. METHODS: Consecutive patients referred to the sleep laboratory with suspected OSA underwent in-laboratory polysomnography (PSG) and simultaneous ODM. The PSG apnea-hypopnea index (AHI) was analyzed using the criteria recommended and accepted by the American Academy of Sleep Medicine (AASM) for the definition of hypopnea: arousal or X3% O 2 desaturation (PSG-AHI 3%) and X4% O 2 desaturation (PSG-AHI 4%), respectively. The results of PSG and ODM were compared by drawing parallels between the PSG-AHI 3% and PSG-AHI 4% with ODM-ODI 3% and ODM-ODI 4% , respectively. Bland-Altman plots, intraclass correlation, receiver operating characteristics (ROC) and area under the curve (AUC) analyses were conducted for statistical evaluation. ClinicalTrial.gov: NCT03526133. RESULTS: This study included 304 participants (men: 55%; age: 55±14 years; body mass index: 30.9±5.7 kg/m 2 ; PSG-AHI 3% : 35.3±30.1/h, ODM-ODI 3% : 30.3±25.9/h). The variability in the AASM scoring bias (PSG-AHI 3% vs PSG-AHI 4%) was significantly higher than that for PSG-AHI 3% vs ODM-ODI 3% (3%) and PSG-AHI 4% vs ODM-ODI 4% (4%) (9.7, 5.0, and 2.9/h, respectively; po0.001). The limits of agreement (2 ± SD, derived from the Bland-Altman plot) of AASM scoring variability were also within the same range for (PSG vs ODM) 3% and 4% variability: 18.9, 21.6, and 16.5/h, respectively. The intraclass correlation/AUC for AASM scoring variability and PSG vs ODM 3% or 4% variability were also within the same range (0.944/0.977 and 0.953/0.955 or 0.971/0.964, respectively). CONCLUSION: Our results showed that ODM is a simple and accurate method for the diagnosis of OSA.

Diagnostic accuracy of oximetry for obstructive sleep apnea: a study on older adults in a home setting

“…Other studies have identified similar values for specificity, but reported the sensitivities of 42.0% ( 14) and 80.0% (15) for detecting mild apnea using ODI (compared to PSG type I). For moderate apnea, we found the same sensitivity as that for mild apnea (66.7%); however, specificity was slightly lower (85.3%) and in an intermediate range compared to the reports in the literature (69.1 to 95.1%) (14,15,20,26,29). For severe apnea, ODI sensitivity was 95.5% and specificity was 88.9%, similar to previously reported studies (14,15,20,29).…”

“…For moderate apnea, we found the same sensitivity as that for mild apnea (66.7%); however, specificity was slightly lower (85.3%) and in an intermediate range compared to the reports in the literature (69.1 to 95.1%) (14,15,20,26,29). For severe apnea, ODI sensitivity was 95.5% and specificity was 88.9%, similar to previously reported studies (14,15,20,29). Evaluation of the degree of correlation to explain the variability of ODI in relation to that of AHI revealed an r of 0.93 and R 2 of 86.17% (po0.05).…”

“…One such study (27) evaluated the parameters of 2, 4, and 6% oxyhemoglobin desaturation from the baseline for event recording, in which the 2% criterion showed better results. Recent studies (14,15,20,29) have reported the sensitivity of ODI for OSA detection to range from 42.03 to 95.1%. In this sample, sensitivity ranged from 66.7 to 95.5% and specificity ranged from 85.3 to 91.8%.…”

“…Advances in technology allow the results of oximetry to be recorded in real time on smartphones, thereby allowing repetitions and storage of data for several nights of sleep, which permits comparisons. These novel advancements were validated against PSG type I, and found to exhibit high sensitivity and specificity (20). A recent historical study that analyzed the use of AHI indicated the need to identify new clinical markers for diagnosing OSA (21).…”

“…Thus, it is necessary to investigate simpler and less expensive methods to expand access to OSA diagnosis. Previous studies (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21) have assessed the ability of pulse oximetry to diagnose OSA; they observed that compared to the apnea-hypopnea index (AHI), the oxyhemoglobin desaturation index (ODI)-measured using the oximeterexhibited high sensitivity and specificity for diagnosing OSA. However, in most studies, validation was performed based on comparison of the test results in a controlled environmente.g., PSG type I in the laboratory-with different sampling designs, thus questions are raised regarding the diagnostic viability of ODI values measured in a laboratory environment for extrapolation in an unsupervised home environment.…”