Reliability and validity of the beck anxiety inventory

Abstract

Two studies were conducted to further psychometric research on the recently developed Beck Anxiety Inventory (BAI). In Study 1 the test-retest reliability and internal consistency of the scale were examined with a sample of 40 outpatients having anxiety disorders. The BAI proved highly internally consistent (cronbach's alpha = .94) and acceptably reliable over an average time lapse of 11 days ( r = .67). Study 2 was conducted to assess the convergent and discriminant validity of the BAI vis á vis anxiety and depression and in comparison to the widely used trait Anxiety measure from the State-Trait Anxiety Inventory. Seventy-one outpatients with anxiety disorders completed the revised State-Trait Anxiety Inventory, the Beck Depression Inventory, and daily diary ratings of anxiety and depression in addition to the BAI. The BAI fared better on tests of convergent and discriminant validity than did Trait Anxiety. The correlation between the BAI and Diary Anxiety was significantly higher than that between BAI and Diary Depression, and, compared to Trait Anxiety, the BAI was significantly less confounded with depression as measured by the BDI. Scores for STAI-Y Trait Anxiety were highly confounded with measures of depression, but results for the STAI-Y State scale were more positive.