Is the Apnea/Hypopnea Index the Best Measure of Obstructive Sleep Apnea?

by Amy Hamaker •

Dr. Jacobowitz believes that widespread adoption will come with greater emphasis on alternative measurements in any clinical trial for OSA. “This isn’t difficult for quality-of-life measures, but it will present a challenge for some other variables such as cardiovascular incidents because they must be measured over a very long time,” he said. “But we have to remember what’s important to the patient and for our health system: how the patient is functioning, and the overall status of their health.”

Amy Hamaker is a freelance medical writer based in California.

The Three Different Definitions of AHI

  • AHIChicago More than 50% decrease in a valid measure of air flow, or a lesser airflow reduction in association with an oxygen desaturation of more than 3%, or an arousal.
  • AHIRec Abnormal respiratory event lasting 10 seconds or more, with 30% or higher reduction in thoracoabdominal movement or airflow, and with 4% or higher oxygen desaturation.
  • AHIAlt 50% or higher reduction in nasal pressure signal excursions and 3% or higher desaturation or arousal.

Source: Laryngoscope. 2012;122:1878-1881

Non-AHI Measurements of OSA

Non-AHI Measurements of OSA

 

  • Biological Measurements (including assessment of hypertension, C-reactive protein, myeloperoxidase, oxygen desaturation, cardiovascular events)
  • Measurements of Sleepiness (including the Epworth Sleepiness Scale)
  • Performance Measurements (including assessment of motor vehicle collisions and psychomotor vigilance tasks)
  • QOL Measurements (including Short Form-36, Nottingham Health Profile, Sickness Impact Profile)

Abstracts from The Laryngoscope

What Is ‘‘Success’’ Following Surgery for Obstructive Sleep Apnea? The Effect of Different Polysomnographic Scoring Systems

ABSTRACT

Objectives/hypothesis: To illustrate that the diagnosis of obstructive sleep apnea (OSA) is dependent on the polysomnographic scoring criteria used, and the success rates of treatments for OSA are dependent on the defined outcome measures.

Study design: Retrospective case series with prospective reanalysis of polysomnographic data.

Methods: Consecutively treated adult patients (N 1/4 40) with moderate to severe OSA having multilevel pharyngeal surgery in 2007 were studied. All patients underwent submucosal lingualplasty and concurrent or previous uvulopalatopharyngoplasty six palatal advancement. Full polysomnography (PSG) was performed preoperatively and at a mean of 145 days postoperatively. Pre- and postoperative PSG data were analyzed by two different but widely used scoring systems for the apnea-hypopnea index (AHI): The American Academy of Sleep Medicine (AASM) 1999 Chicago criteria and the AASM 2007 recommended criteria.

Results: Follow-up PSG data were available in 31 of 40 patients. Successful surgery was defined as a reduction in AHIRec <20 with a 50% reduction from the patient’s baseline, and in this group the surgical intervention was associated with a 72.2% success rate. If, however, differing AHI metrics are used or the absolute or percent reduction used to define a successful outcome is changed, then the rate of surgical success is shown to range from 39% to 92%.