Hierarchical structure and general factor saturation of the Anxiety Sensitivity Index: Evidence and implications

The Anxiety Sensitivity Index (ASI) is one of the most widely used measures of the construct of anxiety sensitivity. Until the recent introduction of a hierarchical model of the ASI by S. Lilienfeld, Turner, and Jacob (1993), the factor structure of the ASI was the subject of debate, with some researchers advocating a unidimensional structure and others proposing multidimensional structures. In the present study, involving 432 outpatients seeking treatment at an anxiety disorders clinic and 32 participants with no mental disorder, the authors tested a hierarchical factor model. The results supported a hierarchical factor structure consisting of 3 lower order factors and 1 higher order factor. It is estimated that the higher order, general factor accounts for 60% of the variance in ASI total scores. The implications of these findings for the conceptualization and assessment of anxiety sensitivity are discussed.