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

Abstract

The coexistence of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA), termed the overlap syndrome (OVS), is associated with adverse outcomes that may be reversed with treatment. However, diagnosis is limited by the apparent need for in-laboratory polysomnography (PSG). WatchPAT is a portable diagnostic device that is validated for the diagnosis of OSA that might represent an attractive tool for the diagnosis of OVS. Subjects with established COPD were recruited from a general population. Subjects underwent PSG and simultaneous recording with WatchPAT. Pulmonary function testing and questionnaires were also performed. A total of 36 subjects were recruited and valid data was obtained on 33 (age 63 ± 7, BMI 28 ± 7, 61% male, FEV 1 56 ± 20% predicted). There was no significant difference in the apnea-hypopnea index (AHI) between PSG and WatchPAT (19 ± 20 versus 20 ± 15 events/h; mean difference 2(-2, 5) events/h; p ¼ 0.381). The AHI was not significantly different in rapid eye movement (REM) and non-rapid eye movement (NREM) determined by PSG versus REM and NREM determined by WatchPAT. WatchPAT slightly overestimated total and REM sleep time, and sleep efficiency. The sensitivity of WatchPAT at an AHI cutoff of !5, !15, and !30 events/h for corresponding PSG AHI cutoffs was 95.8, 92.3, and 88.9, respectively; specificity was 55, 65.0, and 95.8, respectively. WatchPAT is able to determine OSA reliably in patients with COPD. The availability of this additional diagnostic modality may lead to improved detection of OVS, which may in turn lead to improved outcomes for a group of COPD patients at high risk of poor outcomes.

Performance of peripheral arterial tonometry–based testing for the diagnosis of obstructive sleep apnea in a large sleep clinic cohort

“…Several prior studies evaluated the reliability of WatchPat testing, showing strong correlations between AHI and pAHI, in the range of 0.85-0.90. [13][14][15][16][17][18][19][20][21][22][23] First, although the overall correlation coefficient and markers of central tendency such as mean bias and its 95% CI are important, some of the previous publications did not explore or present in detail the high dispersion of the residuals and their practical implications. Second, when evaluating a new device or method of testing, what is of significance to the clinician is not the combination of sensitivity and specificity, but rather the positive and negative predictive values.…”

Improving the performance of peripheral arterial tonometry-based testing for the diagnosis of obstructive sleep apnea

“…Several prior studies had evaluated the reliability of WatchPat 200 testing, showing correlations up to 0.90 between PSG AHI and PAT-based AHI (pAHI), while the practical implications of the large dispersion had been occasionally ignored or deemed negligible. [17][18][19][20][21][22][23][24][25][26][27] Recently, in a point-of-care investigation, we have shown that automatically scored WatchPat 200 tests could lead to significant misclassification rates (30%-50%) in the diagnosis of OSA and its severity against 'gold standard' PSG. 6 In these new analyses of the same 500 participants evaluated with synchronous PSG and PAT-based HSAT devices, we found that the WatchPat 200-derived ODI 4% and Hypoxic burden, in concert with various demographic (age, gender) or anthropometric (BMI, NC) data, can improve the diagnostic accuracy and severity classification of this disease up to 85%-86%.…”

A review of therapies for the overlap syndrome of obstructive sleep apnea and chronic obstructive pulmonary disease

“…Portable and home sleep apnea testing (HSAT) may have adequate sensitivity to diagnose OSA in COPD 59,60 . However, current guidelines recommend against use of HSAT in patients with significant chronic respiratory disease due to the following shortcomings 61 .…”