title: The clinician administered staging instrument for anorexia nervosa: development and psychometric properties.
abstract: OBJECTIVE
  To develop and evaluate an instrument to assess severity in anorexia nervosa (AN), the Clinician Administered Staging Instrument for Anorexia Nervosa (CASIAN).
  
  
  METHODS
  Candidate items for the CASIAN were developed in three phases (domain, content, and item generation) followed by a pilot study. The psychometric properties of the resultant 34-item questionnaire were investigated in cross-sectional and longitudinal samples (N = 171) with DSM-IV AN and subthreshold AN.
  
  
  RESULTS
  Item and factor analysis procedures resulted in a refined 23-item CASIAN comprising of six factors ("Motivation," "Weight," "Illness Duration," "Obsessionality," "Bulimic Behaviors," and "Acute Issues"). The CASIAN had high internal consistency (.811), test-retest (.957), and interrater reliability (.973). Preliminary support for the convergent, discriminant, concurrent, and predictive validity of the CASIAN was found.
  
  
  CONCLUSIONS
  The CASIAN is a psychometrically sound instrument. Further studies are needed to confirm the factor structure and assess its clinical and research utility.
authors.affiliation: School of Psychology, University of Sydney, Sydney, Australia. sarah.maguire@email.cs.nsw.gov.au
authors.forename: Sarah
authors.initials: S
authors.lastname: Maguire
authors.forename: Stephen
authors.initials: S
authors.lastname: Touyz
authors.forename: Lois
authors.initials: L
authors.lastname: Surgenor
authors.forename: Ross D
authors.initials: RD
authors.lastname: Crosby
authors.forename: Scott G
authors.initials: SG
authors.lastname: Engel
authors.forename: Hubert
authors.initials: H
authors.lastname: Lacey
authors.forename: Suzanne
authors.initials: S
authors.lastname: Heywood-Everett
authors.forename: Daniel
authors.initials: D
authors.lastname: Le Grange
mesh_terms: D000293:Adolescent; D000328:Adult; D000856:Anorexia Nervosa / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D006801:Humans; D010865:Pilot Projects; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires