Test-Retest Reliability of Epworth Sleepiness Scale Score in Patients with Untreated Obstructive Sleep Apnea

Study objectives: This study aimed to evaluate the test-retest reliability of the Epworth Sleepiness Scale (ESS) in patients with untreated obstructive sleep apnea (OSA) and investigate the effects of different follow-up techniques and various factors on ESS score discrepancies.

Methods: This study prospectively enrolled participants diagnosed with OSA at West China Hospital of Sichuan University from October 2022 to May 2023. Each participant completed a polysomnography (PSG) and the Chinese version of the ESS. Initial ESS evaluations were performed before the PSG and were reassessed either face-to-face or on telephone within a week. Analysis involved Bland-Altman plots, the intraclass correlation coefficient (ICC), and calculation of mean differences.

Results: We included 382 patients with untreated OSA, averaging 43.52 years old, with a mean body mass index (BMI) of 26.54 kg/m² and an average apnea-hypopnea index (AHI) of 47.93 events/hour. The ICC was recorded at 0.820. The signed difference in ESS scores from baseline to follow-up was 1.68 ± 2.93 overall. In OSA patients with a BMI > 28, the difference was 2.39 ± 3.46, while in those with an AHI ≥ 30, it was 1.77 ± 3.27.

Conclusion: This study underscores the significance of repeated ESS testing to improve the reliability of sleepiness evaluations in patients with OSA. Further studies should aim to confirm these findings in a broader demographic and develop refined methods for more precise sleepiness assessments among different OSA groups.