Anxiety sensitivity is a cognitive, individual difference variable that is differentiated by an individual's fear of anxiety sensations and centred on the belief that such sensations result in harmful consequences. In order to test anxiety sensitivity, Reiss, Peterson, Gursky, and McNally (1986) developed the Anxiety Sensitivity Index (ASI). However, one contentious issue in the area concerns the factor analytic structure of anxiety sensitivity and this has important consequences for the construct. Numerous investigations have been conducted using the ASI, and the results have varied appreciably with some researchers arguing for a unidimensional construct. However the general consensus now is that anxiety sensitivity is multidimensional. It has been argued that the repeated attempts to clarify the dimensionality of anxiety sensitivity, using the 16-item ASI, is problematic because the scale was never designed to measure a multidimensional construct in the first instance. Thus, the objective of the dissertation was to critically examine the anxiety sensitivity construct by using an expanded, multidimensional measure of anxiety sensitivity referred to as the Anxiety Sensitivity Index - Revised ([ASI-R] Taylor & Cox, 1998) and establish the psychometric properties of the measure by conducting a series of empirical investigations to assess the clinical utility of the measure.
A series of three empirical investigations are presented in the current dissertation. The first investigation aimed to critically examine the factor structure and psychometric properties of the ASI-R. Confirmatory factor analysis using a clinical sample of adults revealed that the ASI-R could be improved substantially through the removal of 15 problematic items in order to account for the most robust dimensions of anxiety sensitivity. The modified measure was re-named the 21-item Anxiety Sensitivity Index (21-item ASI) and re-analysed with a large sample of nonclinical adults, revealing configural and metric invariance across groups. Further, comparisons with other alternative models that also include comparisons with previous published ASI models indicated the 21-item ASI to be the best fitting model for both groups. There was also evidence of internal consistency, test-retest reliability, and construct validity for both samples. The aim of the second investigation was to critically examine differences between and within various anxiety classifications, a mood disorder classification, and a nonclinical control sample, with respect to both general and specific dimensions of anxiety sensitivity as identified by the 21-item ASI. In most instances, the results revealed that the differences between and within the diagnostic groups were consistent with theoretical expectations. Finally, the third investigation aimed to examine differences within each diagnostic category before and after cognitive behavioural therapy in order to provide a further test of validity for the revised 21-item ASI. The results revealed significant differences within all but one diagnostic group on the pre and post-treatment scores, using the global and specific dimensions of the 21-item ASI.
The strengths, theoretical contribution, limitations, and directions for future research are discussed. It is concluded that the overall findings relating to the series of empirical investigations presented in the current dissertation make a significant and valid theoretical contribution to the field of anxiety sensitivity in particular, and anxiety research in general, by enhancing our understanding of anxiety sensitivity and how the 21-item ASI can be used to improve therapeutic interventions in clinical practice.
| Identifer | oai:union.ndltd.org:ADTP/264926 |
| Date | January 2004 |
| Creators | Armstrong, Kerry Ann |
| Publisher | Queensland University of Technology |
| Source Sets | Australiasian Digital Theses Program |
| Detected Language | English |
| Rights | Copyright Kerry Ann Armstrong |
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