0580 Scoring WatchPat Studies with Hypopnea Rule 1A (3%) vs Hypopnea Rule 1B (4%), Does it Make a Difference? - A Retrospective Pilot Study

Abstract Introduction Sleep disturbance from respiratory physiology includes a spectrum of disorders associated with snoring, upper airway resistance, and sleep apnea. In the past, treatment of sleep apnea was largely based on its severity as judged by AHI and clinical symptoms. However, increasingly, treatment decisions are being made based on the presence or absence of cardiovascular comorbidities and risk factors. Medicare and many insurance providers require hypopnea to be scored utilizing AASM hypopnea rule 1B (a 4% drop in oxygen saturation). However, this may not be appropriate for younger patients who would be expected to have less desaturation during a respiratory event. This retrospective pilot study examined whether the frequency in which using 3% hypopnea rule vs. 4% hypopnea rule changes reported severity and therefore may affect medical decisions made regarding treatment. Methods Deidentified data from 24 WatchPat sleep studies were analyzed from a sleep practice which primarily serves a rural community. Results were categorized in terms of severity of mild, moderate, and severe based on Hypopnea Rule 1A (3%) against Hypopnea Rule 1B (4%) the latter which is utilized by Medicare. Results Of the 24 studies, 8 had different categories of severity when classification was changed from Rule 1A to Rule 1B. The age group of 20 to 29 was the most greatly affected by the change in classification with 75% of respondents in this category reporting a change. Conclusion WatchPat studies using Rule 1B scoring resulted in a noticeable underestimation of sleep apnea severity among patients aged 20 to 29 when compared with Rule 1A on WatchPAT studies. These findings suggest that reliance on Rule 1B may overlook clinically meaningful respiratory events in younger adults. However, interpretation should be tempered by the small sample size, and larger studies are needed to confirm these age-specific differences. Support (if any)