Respiratory event detection by a positive airway pressure device

Sleep. 2012 Mar 1;35(3):361-7. doi: 10.5665/sleep.1696.


Study objectives: Compare automatic event detection (AED) of respiratory events using a positive airway pressure (PAP) device with manual scoring of polysomnography (PSG) during PAP treatment of obstructive sleep apnea (OSA).

Design: Prospective PSGs of patients using a PAP device.

Setting: Six academic and private sleep disorders centers.

Patients: A total of 148 PSGs from 115 participants with OSA (apnea-hypopnea index [AHI] ≥ 15 events/hr) were analyzed.

Interventions: A signal generated by the PAP device identifying the AED of respiratory events based on airflow was recorded during PSG.

Measurements and results: The PSGs were manually scored without visualization of the AED signal and scoring of a hypopnea required a ≥ 4% oxygen desaturation. The apnea index (AI), hypopnea index (HI), and AHI by manual score and PAP AED were compared. A customized computer program compared individual events by manual scoring and AED to determine the true positive, false positive, false negative, or true negative events and found a sensitivity of 0.58 and a specificity of 0.98. The AHI, AI, and HI by the two methods were highly correlated. Bland-Altman analysis showed better agreement for AI than HI. Using a manually scored AHI of ≥ 10 events/hr to denote inadequate treatment, an AED AHI ≥ 10 events/hr had a sensitivity of 0.58 and a specificity of 0.94.

Conclusions: An AHI < 10 events/hr by PAP AED is usually associated with good treatment efficacy. Differences between manually scored and AED events were primarily due to different criteria for hypopnea detection.

Keywords: APAP; CPAP; autoCPAP.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Algorithms
  • Diagnosis, Computer-Assisted*
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Middle Aged
  • Polysomnography
  • Positive-Pressure Respiration / instrumentation*
  • Predictive Value of Tests
  • ROC Curve
  • Sleep Apnea, Obstructive / complications
  • Sleep Apnea, Obstructive / diagnosis*
  • Sleep Apnea, Obstructive / therapy*
  • Snoring / diagnosis*
  • Snoring / etiology
  • Snoring / therapy
  • Young Adult