Psychomotor Vigilance Test and Epworth Sleepiness Scale in Participants being Evaluated for Sleep Disorders

Excessive daytime sleepiness (EDS) is common in participants with sleep disorders, particularly obstructive sleep apnea (OSA), and can be assessed using the Epworth Sleepiness Scale (ESS) and the Psychomotor Vigilance Test (PVT). However, the relationship between these measures of sleepiness/attention, and their relationships to OSA severity and treatment, remains understudied. This study examined these associations in a sleep center population.

A total of 167 participants, primarily diagnosed or suspected of OSA (n=128 [76.6%]), completed the ESS and PVT during their clinical visit. Associations among ESS, PVT, OSA severity and CPAP adherence were examined using Pearson's correlations, unadjusted and controlling for age, sex and body mass index.

Results showed no significant correlations between ESS and PVT measures of attention/vigilance. While higher ESS scores correlated with more severe apnea-hypopnea index (AHI) in participants with OSA, no association was found with PVT measures. Among participants using continuous positive airway pressure (CPAP), greater hours/night of usage was associated with lower ESS scores, but not with better PVT performance.

Our data indicate that ESS scores track more closely than PVT to OSA severity and treatment. The findings suggest that the tendency to fall asleep as measured by the ESS and attention deficits on PVT may capture different aspects of "sleepiness". While the ESS is commonly used in sleep clinics, further research is needed to determine if PVT should also be used routinely in clinical practice.

Excessive daytime sleepiness (EDS) is a prevalent symptom among individuals with obstructive sleep apnea (OSA), but the relationship between a subjective measure (Epworth Sleepiness Scale) and an objective measure (Psychomotor Vigilance Test) of sleepiness or attention, as well as how each relates to OSA severity and treatment, is not well understood. This study found no association between the ESS and measures from a 3-minute PVT, suggesting that these assessments are not evaluating the same aspects of "sleepiness" reported by participants. Higher ESS scores, but not worse PVT performance, was related to more severe OSA and less adherence to CPAP, indicating that the ESS tracks more closely than the PVT to OSA severity and treatment use.