Oxygen Desaturation Index Differs Significantly Between Types of Sleep Software

Abstract

Study Objectives: The aim of this study was to compare the oxygen desaturation index (ODI) generated by two different sleep software systems. Methods: Participants undergoing diagnostic polysomnography for suspected obstructive sleep apnea underwent simultaneous oximetry recording using the ResMed ApneaLink Plus device (AL) and Compumedics Profusion PSG3 system (Comp). The ODI was calculated by the algorithms in the respective software of each system. To determine if differences were due to algorithm or recording devices, the Comp software was also used to generate ODI values using oximetry data from the AL. Results: In 106 participants, there was good correlation but poor agreement in the ODI generated by the two systems. AL ODI values tended to be higher than Comp ODI values, but with significant variability. For ODI4%, bias was 4.4 events/h (95% limits of agreement −5.8 to 14.6 events/h). There was excellent correlation and agreement when the same oximetry raw data was analyzed by both systems. For ODI4%, bias was 0.03 events/h (95% limits of agreement −2.7 to 2.8 events/h). Similar results were evident when the ODI3% was used. Conclusions: There is a clinically significant difference in ODI values generated by the two systems, likely due to device signal processing, rather than difference in ODI calculation algorithms.

<p>A comparison between auto-scored apnea-hypopnea index and oxygen desaturation index in the characterization of positional obstructive sleep apnea</p>

“…This study avoided variability that results from comparisons from different oximeter brands and filtering characteristics by use of the same oximetry signal. 12,30,31 While it is common for the detection of oxygen desaturation events to be derived based on a minimum decrease from baseline (ie, ≥2%, 3% or 4%), 12,16,17 the algorithm used for this study required a 1% recovery in combination with other parameters. These rules were designed to improve the discrimination between desaturation events attributed to obstructive breathing from events attributed to oximetry drift.…”

Accuracy of WatchPAT for the Diagnosis of Obstructive Sleep Apnea in Patients with Chronic Obstructive Pulmonary Disease

“…Sleep time differences were similar to those reported from other actigraphy technology [23], and are of unclear clinical significance, particularly as they did not seem to impact respiratory event indices substantially. Oximetry technology has previously been shown to vary between devices [24]. Small differences of 2-3% are likely with the margin of error between oximetry and gold-standard arterial co-oximetry or direct PaO 2 measurement, and are unlikely to be clinically significant.…”

Diagnostic accuracy of a two-stage model for detecting obstructive sleep apnoea in chronic tetraplegia

“…A recent study comparing the ODIs generated by a ResMed system with those from a Compumedics system found the ResMed system generated higher values. The source of the difference was in the data collection processes rather than the algorithms built into the software 42. This finding has major implications for the use of ODIs to diagnose OSA and may limit translation of models using oximetry into clinical practice.…”