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Functioning and validity of A Computerized Adaptive Test to measure anxiety (A‐CAT)
Author(s) -
Becker Janine,
Fliege Herbert,
Kocalevent RüyaDaniela,
Bjorner Jakob B.,
Rose Matthias,
Walter Otto B.,
Klapp Burghard F.
Publication year - 2008
Publication title -
depression and anxiety
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.634
H-Index - 129
eISSN - 1520-6394
pISSN - 1091-4269
DOI - 10.1002/da.20482
Subject(s) - anxiety , computerized adaptive testing , discriminant validity , psychology , clinical psychology , item response theory , psychometrics , convergent validity , test validity , beck depression inventory , construct validity , psychiatry , internal consistency
Background: The aim of this study was to evaluate the Computerized Adaptive Test to measure anxiety (A‐CAT), a patient‐reported outcome questionnaire that uses computerized adaptive testing to measure anxiety. Methods: The A‐CAT builds on an item bank of 50 items that has been built using conventional item analyses and item response theory analyses. The A‐CAT was administered on Personal Digital Assistants to n =357 patients diagnosed and treated at the department of Psychosomatic Medicine and Psychotherapy, Charité Berlin, Germany. For validation purposes, two subgroups of patients ( n =110 and 125) answered the A‐CAT along with established anxiety and depression questionnaires. Results: The A‐CAT was fast to complete (on average in 2 min, 38 s) and a precise item response theory based CAT score (reliability>.9) could be estimated after 4–41 items. On average, the CAT displayed 6 items ( SD =4.2). Convergent validity of the A‐CAT was supported by correlations to existing tools (Hospital Anxiety and Depression Scale‐A, Beck Anxiety Inventory, Berliner Stimmungs‐Fragebogen A/D, and State Trait Anxiety Inventory: r =.56–.66); discriminant validity between diagnostic groups was higher for the A‐CAT than for other anxiety measures. Conclusions: The German A‐CAT is an efficient, reliable, and valid tool for assessing anxiety in patients suffering from anxiety disorders and other conditions with significant potential for initial assessment and long‐term treatment monitoring. Future research directions are to explore content balancing of the item selection algorithm of the CAT, to norm the tool to a healthy sample, and to develop practical cutoff scores. Depression and Anxiety, 2008. © 2008 Wiley‐Liss, Inc.