The Research Team at EBTCS is very excited to announce EBTCS’s first scientific publication! The paper was recent published in the Journal of Affective Disorders and examined the properties of a commonly used scale for measuring anxiety symptoms, the Overall Anxiety Severity and Impairment Scale (OASIS). The paper is unique in that is provides information about the properties of this scale in a sample of individuals seeking treatment for anxiety symptoms, something that was missing from the prior literature on this scale. We are so grateful to all of the EBTCS clients who agreed to participate in research as part of their treatment and to the many staff who contributed to this project. We are thrilled to be fulfilling a key part of the EBTCS mission, which is to contribute to the scientific literature in the field of psychology from a practice-based perspective and look forward to many more publications to come. The abstract for the publication is below.
Comorbidity among anxiety-related diagnoses is common, highlighting the need for brief, meaningful measures of anxiety that cut across diagnoses.
The current study examined the psychometric properties of one such measure, the Overall Anxiety Severity and Impairment Scale (OASIS) (Norman et al., 2006), in a naturalistic sample of individuals seeking treatment at an outpatient anxiety treatment center. We examined the measure’s structure, convergent validity, and potential effects of respondent gender. Using ROC analysis, we estimated an optimal cut-score for determining presence of an anxiety disorder in this sample. Finally, we examined the responsiveness of the OASIS to clinical change and calculated a reliable change index.
We found strong psychometric properties of the OASIS. A unitary factor structure with correlated residuals on the first two items provided the best fit to the data. A cut-score of eight best distinguished the presence of an anxiety-related diagnosis. In measurement invariance analyses, we found evidence that men and women respond similarly to the measure. In addition, we found that change in the OASIS was correlated with change in other measures, and we estimated that a four-point change in the OASIS can be considered clinically reliable.
Sample characteristics may limit generalizability. Diagnoses were established by clinicians using a semi-structured interview that, while based upon DSM-IV diagnostic criteria, has not been psychometrically evaluated.
The results provide support for the use of the OASIS in specialty treatment for anxiety-related diagnoses and further highlight the strengths of this measure in clinical practice and research settings.