title: Psychometric properties of the Overall Anxiety Severity and Impairment Scale (OASIS) among psychiatric outpatients.
abstract: The Overall Anxiety Severity and Impairment Scale (OASIS) is a brief, transdiagnostic measure used to assess anxiety severity and related interference. The OASIS has demonstrated strong psychometric properties in previous investigations, however, it has yet to be validated using a transdiagnostic clinician-rated measure.
  
  
  
  We evaluated the factor structure, convergent and discriminant validity, and illness severity cut-scores of the OASIS in a sample of outpatients (N=202).
  
  
  
  A confirmatory factor analysis indicated an unidimensional structure provided the best fit. The OASIS demonstrated good convergent validity and internal consistency. Using the Clinical Global Impression-Severity Scale (CGI-S), ROC curves showed OASIS scores of 6, 10 and 12 to indicate moderate, marked and severe illness severity, respectively.
  
  
  
  The OASIS is a unidimensional self-report measure with good convergent validity and data from the current study provide illness severity cut-scores.
authors.affiliation: Binghamton Anxiety Clinic, Department of Psychology, Binghamton University, United States. Electronic address: lbragdo1@binghamton.edu.
authors.forename: Laura B
authors.initials: LB
authors.lastname: Bragdon
authors.affiliation: Anxiety Disorders Center, The Institute of Living, Hartford Hospital, United States; Yale University School of Medicine, United States.
authors.forename: Gretchen J
authors.initials: GJ
authors.lastname: Diefenbach
authors.affiliation: Anxiety Disorders Center, The Institute of Living, Hartford Hospital, United States.
authors.forename: Scott
authors.initials: S
authors.lastname: Hannan
authors.affiliation: Anxiety Disorders Center, The Institute of Living, Hartford Hospital, United States; Yale University School of Medicine, United States.
authors.forename: David F
authors.initials: DF
authors.lastname: Tolin
mesh_terms: D000328:Adult; D001007:Anxiety / Q000523:psychology; D001008:Anxiety Disorders / Q000175:diagnosis* / Q000523:psychology; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D010045:Outpatients; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D011594:Psychometrics / Q000379:methods; D012372:ROC Curve; D015203:Reproducibility of Results; D057566:Self Report; D012720:Severity of Illness Index
keywords: Anxiety; Assessment; Psychometrics