The Relationship Between Methods of Calculating the AHI and Daytime Sleepiness, Severity of Sleep Apnea, and CPAP Pressure Settings

Kathryn J. Kane, Walden University


Sleep apnea impacts one's mental and physical health, and has social consequences which affect all of society. Not only is there is a weak correlation between the severity of sleep apnea and daytime sleepiness as reported on the Epworth Sleepiness Scale (ESS), but there is also a weak correlation between the severity of sleep apnea and prescribed treatment as indicated by 95th percentile pressure on a continuous positive airway pressure (CPAP) machine. This poses difficulty for providers as well as patients throughout screening and treatment. The purpose of this study was to use a biopsychosocial approach to perform a within-subjects analysis in order to quantitatively investigate methods of calculating the severity of sleep apnea. The study included historical data of 75 participants, each diagnosed with obstructive sleep apnea, prescribed Automatic CPAP therapy, and compliant with treatment. The Apnea Hypopnea Index (AHI) was calculated in the current fashion and also while considering the length of a respiratory event, type of respiratory event, and the combination of these two factors. Linear regression was used to determine if there is a significant difference in the relationships between the AHI and the ESS as well as the AHI and the 95th percentile CPAP pressure. Results endorsed neither a strong relationship between the AHIs and the ESS nor a strong relationship between the AHIs and 95th percentile CPAP pressure either. However, the relationships were somewhat stronger when considering the length and type of the respiratory event. Findings support a need for future research to explore these relationships and offer more accurate screening and treatment of individuals with sleep apnea. Ultimately, those with sleep apnea will experience an improvement in mental, physical and social functioning which may positively impact those without sleep apnea.