Development of the Davos Assessment of Cognitive Biases Scale (DACOBS)
van der Gaag, M × Schütz, C ten Napel, A Landa, Y Delespaul, P Bak5, M Tschacher, W De Hert, Marc #
Elsevier Science Pub. Co.
Schizophrenia Research vol:144 issue:1-3 pages:63-71
Objective: Cognitive problems and biases play an important role in the development and continuation of psychosis.
A self-report measure of these deficits and processes was developed (Davos Assessment of Cognitive
Biases Scale: DACOBS) and is evaluated in this study.
Methods: An item pool made by international experts was used to develop a self-report scale on a sample of
138 schizophrenia spectrum patients. Another sample of 71 patients was recruited to validate the subscales.
A group of 186 normal control subjects was recruited to establish norms and examine discriminative validity.
Results: Factor analyses resulted in seven factors, each with six items (jumping to conclusions, belief inflexibility
bias, attention for threat bias, external attribution bias, social cognition problems, subjective cognitive
problems and safety behavior). All factors independently explained the variance (eigenvalues>2) and total
explained variance was 45%. Reliability was good (Cronbach's alpha=.90; split-half reliability=.92; test–
retest reliability=.86). The DACOBS discriminates between schizophrenia spectrum patients and normal
control subjects. Validity was affirmed for five of seven subscales. The scale ‘Subjective Cognitive problems’
was not associated with objective cognitive functioning and ‘Social cognition problems’ was not associated
with the Hinting task, but with the scale measuring ideas of social reference.
Conclusions: The DACOBS scale, with seven independent subscales, is reliable and valid for use in clinical practice and research.