A Comprehensive Evaluation of a Two-Channel Portable Monitor to “Rule in” Obstructive Sleep Apnea

Abstract

Study Objectives:We hypothesized that a dual-channel portable monitor (PM) device could accurately identify patients who have a high pretest probability of obstructive sleep apnea (OSA), and we evaluated factors that may contribute to variability between PM and polysomnography (PSG) results. Methods: Consecutive clinic patients (N = 104) with possible OSA completed a home PM study, a PM study simultaneous with laboratory PSG, and a second home PM study. Uniform data analysis methods were applied to both PM and PSG data. Primary outcomes of interest were the positive likelihood ratio (LR+) and sensitivity of the PM device to "rule-in" OSA, defi ned as an apnea-hypopnea index (AHI) ≥ 5 events/h on PSG. Effects of different test environment and study nights, and order of study and analysis methods (manual compared to automated) on PM diagnostic accuracy were assessed. Results: The PM has adequate LR+ (4.8), sensitivity (80%), and specifi city (83%) for detecting OSA in the unattended home setting when benchmarked against laboratory PSG, with better LR+ (> 5) and specifi city (100%) and unchanged sensitivity (80%) in the simultaneous laboratory comparison. There were no signifi cant night-night (all p > 0.10) or study order effects (home or laboratory fi rst, p = 0.08) on AHI measures. Manual PM data review improved case fi nding accuracy, although this was not statistically signifi cant (all p > 0.07). Misclassifi cation was more frequent where OSA was mild. Conclusions: Overall performance of the PM device is consistent with current recommended criteria for an "acceptable" device to confi dently "rule-in" OSA (AHI ≥ 5 events/h) in a high pretest probability clinic population. Our data support the utility of simple two-channel diagnostic devices to confi rm the diagnosis of OSA in the home environment.

Oxygen Desaturation Index Differs Significantly Between Types of Sleep Software

“…This finding appears to partly contradict the findings of a previous study by Ward and colleagues. 31 Contrary to our results, they found that the AL was less sensitive than the Comp at diagnosing OSA. However, there are several important differences between their study and ours.…”

Sleep and Long-Term Care

“…43 Unattended home sleep apnea testing using portable monitors is increasingly available for diagnosing OSA, and has demonstrated good sensitivity and specificity for detecting OSA for patients with a high pretest probability. 44,45 Portable, unattended monitoring may be useful for diagnosing OSA in LTC residents who do not have nighttime confusion or dementia. Those with confusion and dementia are likely to remove the portable monitors resulting in a high percentage of missing data.…”

Home Sleep Testing: It's Not How You Play the Game, It's Whether You Win or Lose

“…1 Using a rigorous study protocol of testing the device at home and in the lab (simultaneously with a lab polysomnogram [PSG]) and in a randomized order of testing, they showed that their 2-channel PM (ApneaLink, ResMed, San Diego, CA) was able to reliably confi rm the diagnosis of sleep apnea in those with high pretest likelihood of having OSA (sensitivity 80%, specifi city 83%, positive likelihood ratio 4.8). This study, excepting its limitations, provides much needed validation for the use of a simplifi ed PM to adequately diagnose OSA in a timely fashion in the appropriate patient population.…”

“…Manually scoring the data, rather than relying on the automated scoring algorithm reduced missed cases by up to 18%. 1,4 Similarly, ordering clinicians must be cognizant that PM can underestimate disordered breathing index by as much as 22 events/h. 1 Such results suggest that testing with PM may not only underestimate the severity of disease, but may miss the diagnosis of OSA entirely.…”

“…1,4 Similarly, ordering clinicians must be cognizant that PM can underestimate disordered breathing index by as much as 22 events/h. 1 Such results suggest that testing with PM may not only underestimate the severity of disease, but may miss the diagnosis of OSA entirely. More concerning is the potential for wrong diagnosis of OSA given that most type IV and some type III PM may not be able to adequately differentiate between obstructive and central respiratory events.…”