Validation of a Brief Measure of Anxiety-Related Severity and Impairment

The Overall Anxiety Severity and Impairment Scale (OASIS)

Published In: Journal of Affective Disorders, v. 112, no. 1-3, Jan. 2009, p. 92-101

Posted on RAND.org on December 31, 2008

by Laura Campbell-Sills, Sonya B. Norman, Michelle G. Craske, Greer Sullivan, Ariel J Lang, Denise A. Chavira, Alexander Bystritsky, Cathy D. Sherbourne, Peter Roy-Byrne, Murray Stein

Read More

Access further information on this document at Elsevier Inc.

This article was published outside of RAND. The full text of the article can be found at the link above.

BACKGROUND: The Overall Anxiety Severity and Impairment Scale (OASIS) is a 5-item self-report measure that can be used to assess severity and impairment associated with any anxiety disorder or multiple anxiety disorders. A prior investigation with a nonclinical sample supported the reliability and validity of the OASIS; however, to date it has not been validated for use in clinical samples. METHODS: The present study assessed the psychometric properties of the OASIS in a large sample (N = 1036) of primary care patients whose physicians referred them to an anxiety disorders treatment study. Latent structure, internal consistency, convergent/discriminant validity, and cut-score analyses were conducted. RESULTS: Exploratory and confirmatory factor analyses supported a unidimensional structure. The five OASIS items displayed strong loadings on the single factor and had a high degree of internal consistency. OASIS scores demonstrated robust correlations with global and disorder-specific measures of anxiety, and weak correlations with measures of unrelated constructs. A cut-score of 8 correctly classified 87% of this sample as having an anxiety diagnosis or not. LIMITATIONS: Convergent validity measures consisted solely of other self-report measures of anxiety. Future studies should evaluate the convergence of OASIS scores with clinician-rated and behavioral measures of anxiety severity. CONCLUSIONS: Overall, this investigation suggests that the OASIS is a valid instrument for measurement of anxiety severity and impairment in clinical samples. Its brevity and applicability to a wide range of anxiety disorders enhance its utility as a screening and assessment tool.

This report is part of the RAND Corporation external publication series. Many RAND studies are published in peer-reviewed scholarly journals, as chapters in commercial books, or as documents published by other organizations.

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.