Even with CPAP adherence, some obstructive sleep apnea (OSA) patients remain excessively sleepy during the day—impacting their cognition, mood, and quality of life. This webinar examines why, from overlooked sleep insufficiency to brain changes that started before therapy, and details how to assess these patients beyond the standard Epworth Sleepiness Scale and CPAP data downloads. Join us for a dive into the prevalence, hidden drivers, and clinical detection of persistent daytime sleepiness in treated OSA. By attending this webinar, you will be able to:Discuss the prevalence and patient impact of excessive daytime sleepiness that persists despite OSA therapy adherence. Evaluate the role of tools such as the ESS, MSLT, and functional outcome measures, including their thresholds and limitations.