@article {227,
	title = {An evaluation of patient-reported outcomes found computerized adaptive testing was efficient in assessing stress perception},
	journal = {Journal of Clinical Epidemiology},
	volume = {62},
	number = {3},
	year = {2009},
	note = {Kocalevent, Ruya-DanielaRose, MatthiasBecker, JanineWalter, Otto BFliege, HerbertBjorner, Jakob BKleiber, DieterKlapp, Burghard FEvaluation StudiesUnited StatesJournal of clinical epidemiologyJ Clin Epidemiol. 2009 Mar;62(3):278-87, 287.e1-3. Epub 2008 Jul 18.},
	pages = {278-287},
	edition = {2008/07/22},
	abstract = {OBJECTIVES: This study aimed to develop and evaluate a first computerized adaptive test (CAT) for the measurement of stress perception (Stress-CAT), in terms of the two dimensions: exposure to stress and stress reaction. STUDY DESIGN AND SETTING: Item response theory modeling was performed using a two-parameter model (Generalized Partial Credit Model). The evaluation of the Stress-CAT comprised a simulation study and real clinical application. A total of 1,092 psychosomatic patients (N1) were studied. Two hundred simulees (N2) were generated for a simulated response data set. Then the Stress-CAT was given to n=116 inpatients, (N3) together with established stress questionnaires as validity criteria. RESULTS: The final banks included n=38 stress exposure items and n=31 stress reaction items. In the first simulation study, CAT scores could be estimated with a high measurement precision (SE<0.32; rho>0.90) using 7.0+/-2.3 (M+/-SD) stress reaction items and 11.6+/-1.7 stress exposure items. The second simulation study reanalyzed real patients data (N1) and showed an average use of items of 5.6+/-2.1 for the dimension stress reaction and 10.0+/-4.9 for the dimension stress exposure. Convergent validity showed significantly high correlations. CONCLUSIONS: The Stress-CAT is short and precise, potentially lowering the response burden of patients in clinical decision making.},
	keywords = {*Diagnosis, Computer-Assisted, Adolescent, Adult, Aged, Aged, 80 and over, Confidence Intervals, Female, Humans, Male, Middle Aged, Perception, Quality of Health Care/*standards, Questionnaires, Reproducibility of Results, Sickness Impact Profile, Stress, Psychological/*diagnosis/psychology, Treatment Outcome},
	isbn = {1878-5921 (Electronic)0895-4356 (Linking)},
	author = {Kocalevent, R. D. and Rose, M. and Becker, J. and Walter, O. B. and Fliege, H. and Bjorner, J. B. and Kleiber, D. and Klapp, B. F.}
}
@article {20,
	title = {Functioning and validity of a computerized adaptive test to measure anxiety (A CAT)},
	journal = {Depression and Anxiety},
	volume = {25},
	number = {12},
	year = {2008},
	pages = {E182-E194},
	abstract = {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, Charit{\'e} 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{\textendash}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{\textendash}.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. {\textcopyright} 2008 Wiley-Liss, Inc.},
	isbn = {1520-6394},
	author = {Becker, J. and Fliege, H. and Kocalevent, R. D. and Bjorner, J. B. and Rose, M. and Walter, O. B. and Klapp, B. F.}
}
@article {2084,
	title = {Validating the German computerized adaptive test for anxiety on healthy sample (A-CAT)},
	journal = {Quality of Life Research},
	volume = {13},
	year = {2004},
	pages = {1515},
	author = {Becker, J. and Walter, O. B. and Fliege, H. and Bjorner, J. B. and Kocalevent, R. D. and Schmid, G. and Klapp, B. F. and Rose, M.}
}
