Development and validation of the Hypersomnia Severity Index (HSI): A measure to assess hypersomnia severity and impairment in psychiatric disorders. (November 2019)

• Record Type: Journal Article
• Authors: Kaplan, Katherine A; Plante, David T; Cook, Jesse D; Harvey, Allison G
• Is Part Of: Psychiatry research. Volume 281(2019)
• Publication Date: 2019-11
• Subjects: Sleepiness -- Long sleep -- Hypersomnolence -- Self-report -- Mood disorders -- Psychometric validation -- Assessment; Psychiatry -- Periodicals; Psychiatry -- periodicals; Psychiatrie -- Périodiques; 616.89
• DOI: 10.1016/j.psychres.2019.112547
• Languages: English
• ISSNs: 0165-1781

Abstract

Highlights: Hypersomnia is common across mood disorders and associated with significant illness burden. We validated a self-report instrument to measure its severity, distress and impairment. The Hypersomnia Severity Index showed good convergent validity against existing sleep measures. Favorable construct validity was established against two weeks of sleep diaries and actigraphy. Abstract: Hypersomnia is common in psychiatric disorders, yet there are few self-report measures that adequately characterize this sleep disturbance. The objective of this study was to validate the Hypersomnia Severity Index (HSI), a tool designed to measure severity, distress and impairment of hypersomnia in psychiatric populations. Psychometric properties were evaluated in an undergraduate Scale Development sample ( N = 381) and two psychiatric Scale Validation samples: euthymic bipolar participants with a range of sleep complaints ( N = 89), and unmedicated unipolar depressed participants ( N = 21) meeting operational criteria for hypersomnolence disorder. Exploratory factor analysis and confirmatory factor analysis in the Scale Development and Validation samples, respectively, suggested a two-factor structure representing Hypersomnia Symptoms and Distress/Impairment best fit the data. Convergent validity was established by significant associations with the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and the Sheehan Disability Scale in both samples. Construct validity was further supported by significant correlations between the Scale Validation sample and two weeks of diary- and actigraphy-determined total sleep time and time in bed. A cutoff score of 10 maximally discriminated between those with hypersomnia and those without. The HSI shows promise as a measure of hypersomnia that is commonly seen in psychiatric disorders, and may be of use to both researchers and clinicians. Support: This work is supported by grants from the American Sleep Medicine Foundation (76-JF-12 ), the Brain and Behavior Research Foundation (19193 ), and NIMH K23MH099234 (DTP); National Science Foundation Graduate Research Fellowship Program and Stanford Child Health Research Institute (KAK); and R34MH080958 and R01MH105513 (AGH).