The anxiety sensitivity index:

Reliability, factor structure, and factor independence from other anxiety measures for the Anxiety Sensitivity Index (ASI) was assessed. One hundred and twenty-two anxious college students were administered the ASI, Cognitive-Somatic Anxiety Questionnaire, and the Reactions to Relaxation and Arousal Questionnaire. The results suggest that the ASI is a reliable measure which is factorially independent of other anxiety measures. Further, the ASI was supported as a measure of the variable anxiety sensitivity which has been suggested as an important personality variable in fear behavior.