Comparison of a simple obstructive sleep apnea screening device with standard in-laboratory polysomnography

Background: Obstructive sleep apnea (OSA) is a common underdiagnosed sleep disorder. Various strategies have been employed to easily screen for OSA. The ApneaStrip® (AS - S.L.P. Ltd, Tel Aviv, Israel) is an FDA approved OSA screening device applied to the upper lip at home. We evaluated the performance of this device against simultaneous in-laboratory polysomnography (PSG) in a group of well-characterized OSA patients.

Methods: Diagnostic PSG was performed in 56 patients (29 M, 37 F; age 48.9 ± 14.6 years; body mass index [BMI] 37.5 ± 9.0 kg/m(2); apnea-hypopnea index-events/h-[AHI] 32.8 ± 22.9). The AS was applied and positioned to detect nasal and oral airflow. The AS gives a "positive" result for AHI ≥ 15. We examined the sensitivity and specificity of the AS against three thresholds derived from PSG: AHI ≥ 5, AHI ≥ 15 (company recommendation), and AHI ≥ 30.

Results: For PSG AHI ≥ 15, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the AS were 80, 54.5, 87.8, and 40 %, respectively. For PSG AHI ≥ 5, the values were 75.1, 66.7, 97.1, and 13.3 %, respectively. For PSG AHI ≥ 30, the values were 86.9, 36.2, 48.8, and 80 %, respectively. There were no significant modifying effects of age, BMI, gender, hypertension, diabetes, lung disease, and heart disease.

Conclusion: The AS has a high sensitivity for detection of OSA with AHI ≥ 15, but only modest specificity. The AS could be a useful component of an OSA screening program; however, negative results should be interpreted cautiously.