Psychometric properties of the Overall Anxiety Severity and Impairment Scale (OASIS) among psychiatric outpatients

J Affect Disord. 2016 Sep 1:201:112-5. doi: 10.1016/j.jad.2016.05.005. Epub 2016 May 10.

Abstract

Background: 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.

Methods: We evaluated the factor structure, convergent and discriminant validity, and illness severity cut-scores of the OASIS in a sample of outpatients (N=202).

Results: 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.

Conclusions: The OASIS is a unidimensional self-report measure with good convergent validity and data from the current study provide illness severity cut-scores.

Keywords: Anxiety; Assessment; Psychometrics.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Anxiety / psychology
  • Anxiety Disorders / diagnosis*
  • Anxiety Disorders / psychology
  • Factor Analysis, Statistical
  • Female
  • Humans
  • Male
  • Outpatients
  • Psychiatric Status Rating Scales / standards*
  • Psychometrics / methods
  • ROC Curve
  • Reproducibility of Results
  • Self Report
  • Severity of Illness Index