Milton Erman1, Helene Emsellem2, Jed Black3, Fannie Mori4, Geert Mayer5. 1. Pacific Sleep Medicine, Oceanside, CA, USA. Electronic address: erman@pacificsleepmedicine.net. 2. The Center for Sleep & Wake Disorders, Chevy Chase, MD, USA. 3. Stanford Sleep Medicine Center, Redwood City, CA, USA; Jazz Pharmaceuticals, Inc., Palo Alto, CA, USA. 4. Jazz Pharmaceuticals, Inc., Palo Alto, CA, USA. 5. Klinik, Department of Neurology Schwalmstadt-Treysa, Germany.
Abstract
BACKGROUND: In evaluating pathologic sleepiness, the Epworth Sleepiness Scale (ESS) assesses subjective sleep propensity; the Maintenance of Wakefulness Test (MWT) is an objective measure of the ability to stay awake. This analysis evaluated the strength of the correlation between ESS and MWT with regard to absolute values in scores. METHODS: Data were analyzed separately from the intent-to-treat populations of two eight-week clinical trials of sodium oxybate for the treatment of narcolepsy, SXB-15 and SXB-22. For all treatment groups, correlations between ESS and MWT were evaluated at baseline, week four, and week eight using the Pearson product-moment correlation coefficient. RESULTS: Overall, correlations across all treatment groups in each study described an inverse relationship, reflecting the scoring of each measure (ie, whereas higher ESS scores indicate greater sleepiness, higher MWT scores indicate a greater ability to remain awake). Significant correlations of low-to-moderate strength were observed at all time points in both studies. In SXB-15, correlation coefficients were -0.272, -0.365, and -0.343 at baseline (n = 221), week four (n = 212), and week eight (n = 205), respectively, with all P < 0.0001. Similarly, in SXB-22, correlation coefficients were -0.302 (n = 216), -0.418 (n = 211), and -0.432 (n = 196) at the three time points, respectively, also with all P < 0.0001. CONCLUSION: Although all correlations showed statistical significance, they were of low-to-moderate strength. These results indicate that ESS and MWT measure features of pathologic sleepiness that may be distinct, but partially overlapping. These data corroborate those of other studies, suggesting that physiologic mechanisms that regulate alertness and sleep propensity may function somewhat independently.
RCT Entities:
BACKGROUND: In evaluating pathologic sleepiness, the Epworth Sleepiness Scale (ESS) assesses subjective sleep propensity; the Maintenance of Wakefulness Test (MWT) is an objective measure of the ability to stay awake. This analysis evaluated the strength of the correlation between ESS and MWT with regard to absolute values in scores. METHODS: Data were analyzed separately from the intent-to-treat populations of two eight-week clinical trials of sodium oxybate for the treatment of narcolepsy, SXB-15 and SXB-22. For all treatment groups, correlations between ESS and MWT were evaluated at baseline, week four, and week eight using the Pearson product-moment correlation coefficient. RESULTS: Overall, correlations across all treatment groups in each study described an inverse relationship, reflecting the scoring of each measure (ie, whereas higher ESS scores indicate greater sleepiness, higher MWT scores indicate a greater ability to remain awake). Significant correlations of low-to-moderate strength were observed at all time points in both studies. In SXB-15, correlation coefficients were -0.272, -0.365, and -0.343 at baseline (n = 221), week four (n = 212), and week eight (n = 205), respectively, with all P < 0.0001. Similarly, in SXB-22, correlation coefficients were -0.302 (n = 216), -0.418 (n = 211), and -0.432 (n = 196) at the three time points, respectively, also with all P < 0.0001. CONCLUSION: Although all correlations showed statistical significance, they were of low-to-moderate strength. These results indicate that ESS and MWT measure features of pathologic sleepiness that may be distinct, but partially overlapping. These data corroborate those of other studies, suggesting that physiologic mechanisms that regulate alertness and sleep propensity may function somewhat independently.
Authors: David G Ingram; Ann Marie Marciarille; Zarmina Ehsan; Gayln V Perry; Teresa Schneider; Baha Al-Shawwa Journal: Sleep Breath Date: 2019-02-08 Impact factor: 2.816
Authors: Michael J Thorpy; Colin Shapiro; Geert Mayer; Bruce C Corser; Helene Emsellem; Giuseppe Plazzi; Dan Chen; Lawrence P Carter; Hao Wang; Yuan Lu; Jed Black; Yves Dauvilliers Journal: Ann Neurol Date: 2019-03 Impact factor: 10.422
Authors: Aleksandar Videnovic; Amy W Amara; Cynthia Comella; Paula K Schweitzer; Helene Emsellem; Kris Liu; Amanda L Sterkel; Mildred D Gottwald; Joshua R Steinerman; Philip Jochelson; Katie Zomorodi; Robert A Hauser Journal: Mov Disord Date: 2021-06-30 Impact factor: 10.338