title: A psychometric study of the Fear of Sleep Inventory-Short Form (FoSI-SF).
abstract: OBJECTIVE
  Fear of sleep may play a significant role in sleep disturbances in individuals with posttraumatic stress disorder (PTSD). This report describes a psychometric study of the Fear of Sleep Inventory (FoSI), which was developed to measure this construct.
  
  
  METHODS
  The psychometric properties of the FoSI were examined in a non-clinical sample of 292 college students (Study I) and in a clinical sample of 67 trauma-exposed adults experiencing chronic nightmares (Study II). Data on the 23 items of the FoSI were subjected to exploratory factor analyses (EFA) to identify items uniquely assessing fear of sleep. Next, reliability and validity of a 13-item version of the FoSI was examined in both samples.
  
  
  RESULTS
  A 13-item Short-Form version (FoSI-SF) was identified as having a clear 2-factor structure with high internal consistency in both the non-clinical (α = 0.76-0.94) and clinical (α = 0.88-0.91) samples. Both studies demonstrated good convergent validity with measures of PTSD (0.48-0.61) and insomnia (0.39-0.48) and discriminant validity with a measure of sleep hygiene (0.19-0.27). The total score on the FoSI-SF was significantly higher in the clinical sample (mean = 17.90, SD = 12.56) than in the non-clinical sample (mean = 4.80, SD = 7.72); t(357) = 8.85 p < 0.001.
  
  
  CONCLUSIONS
  Although all items are recommended for clinical purposes, the data support the use of the 13-item FoSI-SF for research purposes. Replication of the factor structure in clinical samples is needed. Results are discussed in terms of limitations of this study and directions for further research.
authors.affiliation: The University of Texas Health Science Center at San Antonio, San Antonio, TX.
authors.forename: Kristi E
authors.initials: KE
authors.lastname: Pruiksma
authors.affiliation: The University of North Texas, Denton, TX.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Taylor
authors.affiliation: The University of North Texas, Denton, TX.
authors.forename: Camilo
authors.initials: C
authors.lastname: Ruggero
authors.affiliation: The University of North Texas, Denton, TX.
authors.forename: Adriel
authors.initials: A
authors.lastname: Boals
authors.affiliation: The University of Tulsa, Tulsa, OK.
authors.forename: Joanne L
authors.initials: JL
authors.lastname: Davis
authors.affiliation: The University of Tulsa, Tulsa, OK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Cranston
authors.affiliation: Veterans Affairs Connecticut Health Care System, University of Connecticut School of Medicine, Farmington, CT ; Yale School of Medicine, New Haven, CT.
authors.forename: Jason C
authors.initials: JC
authors.lastname: DeViva
authors.affiliation: The Geisel School of Medicine at Dartmouth, Hanover, NH.
authors.forename: Claudia
authors.initials: C
authors.lastname: Zayfert
mesh_terms: D000328:Adult; D004325:Dreams / Q000523:psychology; D005163:Factor Analysis, Statistical; D005239:Fear / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D011594:Psychometrics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012890:Sleep; D013313:Stress Disorders, Post-Traumatic / Q000523:psychology; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: PTSD; fear of sleep; insomnia; nightmares; posttraumatic stress disorder; trauma