Psychometric Characteristics of the Insomnia Severity Index in Veterans With History of Traumatic Brain Injury

Behav Sleep Med. Jan-Feb 2019;17(1):12-18. doi: 10.1080/15402002.2016.1266490. Epub 2017 Jan 18.

Abstract

Objective/background: The Insomnia Severity Index (ISI) is a widely used self-report measure of insomnia symptoms. However, to date this measure has not been validated or well-characterized in veterans who have experienced traumatic brain injury (TBI). This study assessed the psychometric properties and convergent, divergent, construct, and discriminate validity of the ISI in veterans with a history of TBI.

Participants: Eighty-three veterans with history of TBI were seen in the VA San Diego Healthcare System as part of a research protocol.

Methods: Measures included the ISI, Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, Neurobehavioral Symptom Inventory, Beck Depression Inventory-II, Beck Anxiety Inventory, and PTSD Checklist-Military Version.

Results: The ISI demonstrated moderate to strong or excellent convergent and divergent validity. A principal component analysis indicated a single construct with excellent internal consistency (Cronbach's alpha = 0.92). In exploratory analyses, the ISI discriminated well between those with (73%) and without (27%) sleep disturbance based on the PSQI.

Conclusions: Results from this study indicate validity of the ISI in assessing insomnia in veterans with history of TBI and suggest a cutoff score not dissimilar from non-TBI populations. Findings from this study can help inform clinical applicability of the ISI, as well as future studies of insomnia in TBI.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Brain Injuries, Traumatic / complications*
  • Brain Injuries, Traumatic / pathology
  • Brain Injuries, Traumatic / psychology
  • Female
  • Humans
  • Male
  • Psychometrics / methods*
  • Reproducibility of Results
  • Self Report
  • Severity of Illness Index
  • Sleep Initiation and Maintenance Disorders / diagnosis*
  • Sleep Initiation and Maintenance Disorders / pathology
  • Veterans / psychology*