Multistate Modeling for Determining Transition Probabilities in Sleep Apnea Severity Across Multiple Nights of Recording

To the Editor:
OSA is one of the most frequent chronic diseases associated with a high burden on individuals, health systems, and society. In recent years, the internight variability in OSA severity has emerged as a highly intriguing subject in sleep medicine. It was considered primarily as an obstacle to certainty in clinical decision-making because substantial variability is associated with misdiagnosis (20%-60% on any given night) and potentially incorrect treatment indications.1 Repeated assessments have been proposed as a solution to mitigate the risk of errors. However, perceptions are shifting toward viewing this variability in severity as a clinical characteristic of OSA, similar to the dynamic progression seen in COPD, asthma, or hypertension. Studies have found that excessive night-to-night variability in OSA severity is also associated with the risk of adverse health outcomes, including higher BP and increased likelihood of atrial fibrillation events.2,3