Reliability of Manual and Automatic Scoring of Single Channel Nasal Airflow Device (ApneaLink) in Determining Moderate or Severe Obstructive Sleep Apnea Syndrome

Obstructive sleep apnea (OSA) is associated with cardiovascular, cerebrovascular, and metabolic disease.1-3 Treatment of OSA with continuous positive airway pressure (CPAP) can ameliorate high blood pressure4 and insulin resistance.5 Because OSA is a prevalent disorder affecting 4.5% and 3.2% of Korean men and women, respectively,6 adequate screening for the disease is a major health issue. The gold standard for diagnosis of OSA is overnight polysomnography (PSG). However, PSG studies are expensive and labor intensive.7 Portable monitoring devices allow screening for disordered breathing during sleep with lower cost and more convenience; however, their reliability has always been a concern. Practice parameters for the use of portable monitoring devices published in 2003 discourage the use of type 4 (oneor two-channel devices including oxygen saturation or airflow) to identify an apnea-hypopnea index (AHI) of greater or less than 15. However, recent findings suggest that a single-channel portable monitoring device as a home sleep test can be effective in diagnosing OSA and making related therapeutic decisions.8,9 ApneaLink (AL) is a type 4 single-channel monitoring device. The pressure transducer in AL is connected to a nasal cannula inserted into the user’s nostrils, and it records nasal airflow. AL software then automatically analyzes the data and produces a 1-page report that contains the AHI, apnea index (AI) and hypopnea index (HI). Apnea and hypopnea can be measured Received: November 28, 2016 Revised: December 19, 2016 Accepted: December 26, 2016