Sleep Breath

PurposeHome sleep testing devices are being widely used in diagnosis/screening for obstructive sleep apnea (OSA). We examined differences in OSA metrics obtained from two devices with divergent home monitoring strategies; the Apnea Risk Evaluation System (ARES\u2122, multiple signals plus forehead reflectance oximetry) and the Nonin WristOx2\u2122 (single channel finger transmission pulse oximeter), compared to differences from night-night variability of OSA.Methods152 male / 26 female subjects (BMI=30.3\ub15.6 kg/m2, age=52.5\ub18.9 yrs) were recruited without regard to OSA symptoms, and simultaneously wore both ARES\u2122 and Nonin WristOx2\u2122 for 2 nights (n=351 nights). Automated analysis of the WristOx2 yielded ODIOx2 (Oxygen Desaturation Index, # 654% O2 dips/hr) and automated analysis with manual editing of ARES\u2122 yielded AHI4ARES (apneas+hypopneas with 654% O2 dips/hr) and RDIARES (apneas+ hypopneas with 654% O2 dips/hr or arousal surrogates). Baseline awake oxygen saturation, percent time <90% O2 saturation (% time <90% O2Sat) and O2 signal loss were compared between the two methods.ResultsCorrelation between AHI4ARES and ODIOx2 was high (ICC=0.9, 95% CI=0.87\u20130.92, p<0.001, bias\ub1SD=0.7\ub16.1 events/hr). Agreement values for OSA diagnosis (77\u201385%) between devices was similar to that seen from night-to-night variability of OSA using a single device. Awake baseline O2 saturation was significantly higher in the ARES\u2122 (96.2\ub11.6%) than WristOx2\u2122 (92.2\ub12.1%, p<0.01). There was a significantly lower %time<90% O2Sat reported by the ARES\u2122 compared to WristOx2 (median (IQR) 0.5(0.0, 2.6) vs 2.1(0.3, 9.7), p<0.001) and the correlation was low (ICC=0.2).ConclusionsOSA severity metrics predominantly dependent on change in oxygen saturation and metrics used in diagnosis of OSA (AHI4 and ODI) correlated well across devices tested. However differences in cumulative oxygen desaturation measures (i.e.% time