0571 Impact of CPAP Adherence on Objective and Subjective Sleepiness Measures

Abstract Introduction Sleepiness, a common symptom of various sleep disorders, has been subjectively measured using the Epworth Sleepiness Scale (ESS) and objectively quantified using the Psychomotor Vigilance Test (PVT). The relative merit of these two measures of sleepiness has been debated, and both have shown inconsistent relationships with severity of obstructive sleep apnea (OSA) and responses to treatment. We report the relative associations of ESS and PVT with hours of CPAP use within a clinical sample. Methods Patients being evaluated for sleep disorders at the University of Pennsylvania’s Sleep Center competed both the ESS and PVT measurements in a single clinical visit. Thirty-nine patients had a diagnosis of OSA and were currently using CPAP. Pearson’s correlations were utilized to examine the association between CPAP adherence and both the ESS and PVT measures (transformed lapses sum of square root of number of lapses and square root of lapses+1) and mean reciprocal response time (RRT). Results total of 39 patients (64.1% males; 52.6% White, 39.5% Black) were studied, with a mean (SD) age of 61.1 (16.4) years and BMI of 35.2 (9.5) kg/m2; residual apnea-hypopnea index (AHI) was 6.5 (10.8) events/hour (23 63.9% had residual AHI 5 events/hour). Participants used CPAP an average of 5.87 (2.27) hours/night in the past 30 days, 5.87 (2.47) hours/night over the past 7 days, and 5.91 (2.86) hours/night the day prior to ESS/PVT measurement. Overall, we observed a strong correlation between less subjective sleepiness based on ESS and more CPAP usage at 30-days (rho = -0.48, p=0.002), 7-days (rho = -0.43, p=0.006) and the prior day (rho = -0.38, p=0.017). However, there was no correlation between hours/night of CPAP adherence and objective function as measured on PVT. Conclusion Among patients with OSA using CPAP evaluated at University of Pennsylvania’s Sleep Center, greater amounts of CPAP use were significantly associated with lower ESS scores (e.g., less sleepiness). Conversely, no significant correlations were observed between CPAP use and objective data on PVT. Larger studies examining the causal effects of CPAP on subjective and objective sleepiness, including with repeat assessments of ESS and PVT during therapy, are warranted. Support (if any)