title: Psychometric Validation of the Insomnia Severity Index in Adults with Sickle Cell Disease.
abstract: BACKGROUND
  The Insomnia Severity Index (ISI) is an instrument to evaluate insomnia symptoms. The psychometric properties have not been established in adults (18 years of age or older) with sickle cell disease (SCD).
  
  
  OBJECTIVE
  Evaluate the reliability and validity of the ISI among adults with SCD.
  
  
  METHODS
  Analysis included psychometric evaluation with exploratory factor analysis.
  
  
  RESULTS
  Our 263 participants had a mean age of 35.6 years and primarily were female (54.8%) with HbSS genotype (69.2%). Almost 41% were classified as clinical insomnia cases (ISI ≥14) using the traditional scoring approach. Two factors,Insomnia SymptomsandInsomnia Impact, emerged during factor analysis. Reliability of both factor-scales was good and each correlated with pain severity and depressive symptomatology (r= 0.38 to 0.66, p<.01).
  
  
  CONCLUSIONS
  The ISI demonstrated construct validity and reliability for evaluating insomnia symptomatology among adults with SCD and can be used in research and clinical practice.
authors.affiliation: Johns Hopkins University School of Nursing.
authors.forename: Gyasi
authors.initials: G
authors.lastname: Moscou-Jackson
authors.affiliation: Johns Hopkins University School of Nursing.
authors.forename: Jerilyn
authors.initials: J
authors.lastname: Allen
authors.affiliation: Johns Hopkins University School of Medicine.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Smith
authors.affiliation: Johns Hopkins Berman Institute of Bioethics.
authors.forename: Carlton
authors.initials: C
authors.lastname: Haywood
keywords: Anemia, sickle cell; factor analysis, statistical; questionnaires; validation studies