STUDY OBJECTIVES: The objective of this study was to measure fatigue and hypersomnolence in patients with obstructive sleep apnea (OSA) treated with a mandibular advancement device (MAD), using Epworth Sleepiness Scale (ESS) for hypersomnolence and Checklist Individual Strength questionnaire (CIS20R) for fatigue. METHODS: This was a single-center, prospective cohort study. A total of 58 patients with OSA filled out ESS and CIS20R questionnaires at baseline and after 3 months of MAD treatment. A total of 39 full datasets were collected. Statistical analysis for reliability of the questionnaires, comparison between baseline and 3-month follow-up, correlation between the changes in the values of the two questionnaires, and changes in apnea-hypopnea index (AHI) were performed. RESULTS: CIS20R showed excellent reliability in this patient group at baseline and 3-month follow-up (Cronbach α = .97), ESS showed a marginally good reliability (Cronbach α = .82). The CIS20R (82/140) expressed high levels of fatigue at baseline, and ESS showed a normal level of daytime sleepiness. AHI, ESS, and CIS20R were significantly reduced under MAD treatment. A significant correlation between ESS and CIS20R was observed. No significant correlation between any of the questionnaires and the change in AHI was found. CONCLUSIONS: The CIS20R questionnaire results showed a high level of fatigue in the patients with OSA, and the questionnaire can be used to evaluate changes in fatigue due to MAD treatment after 3 months. The ESS failed to show similar characteristics. Therefore, a combination of ESS for hypersomnolence with CIS20R for fatigue is proposed for the follow-up of patients with OSA treated with MAD.
