Validation of a brief measure of anxiety-related severity and impairment: the Overall Anxiety Severity and Impairment Scale (OASIS).
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.


CONCLUSIONS
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.
Campbell-Sills
Laura
L
Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093-0603, USA. campbell-sills@ucsd.edu
Norman
Sonya B
SB
Craske
Michelle G
MG
Sullivan
Greer
G
Lang
Ariel J
AJ
Chavira
Denise A
DA
Bystritsky
Alexander
A
Sherbourne
Cathy
C
Roy-Byrne
Peter
P
Stein
Murray B
MB
D000293:Adolescent; D000328:Adult; D000368:Aged; D001008:Anxiety Disorders / Q000175:diagnosis / Q000523:psychology; D003937:Diagnosis, Differential; D005069:Evaluation Studies as Topic; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D010555:Personality Inventory / Q000592:standards / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests; D011320:Primary Health Care / Q000379:methods; D011594:Psychometrics; D012372:ROC Curve; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires