Reliability and validity of the Davos Assessment of Cognitive Biases Scale

Abstract

Objective To import the Davos Assessment of Cognitive Biases Scale(DACOBS) and evaluate the reliability and validity of it. Methods Authorized by the original authors, the English version of DACOBS was translated into Chinese. By convenience sampling method, 102 schizophrenic patients who met the DSM-Ⅳ diagnostic criteria and 120 community residents and college students were selected and assessed with the DACOBS for item analysis, exploratory factor analysis (EFA) and internal consistency analysis. The Cognitive Bias Questionnaire (CBQ), Beck Depression Inventory (BDI), Peters et al. Delusions Inventory (PDI) and Psychotic Symptoms Rating Scale (PSYRATS) were administered to test the criterion-related validity. Independent samples t-tests were used to test the discriminant validity. Results (1)After project analysis, items 1, 3 and 12 were deleted. Seven components were extracted via exploratory factor analysis, and a variance of 54.04% was explained. Factor loading for all items of DACOBS-C ranged from 0.42 to 0.74. The total score of DACOBS-C was significantly correlated with scores of CBQ(r= 0.55,P< 0.01), BDI(r= 0.61, P< 0.01), PDI sub-scale(r= 0.60, 0.63, 0.56, 0.57, respectively, P< 0.01 for all) and PSYRATS(r= 0.57, P< 0.01). The DACOBS-C score of the patients was higher than that of the controls ((139.23±33.33) vs. (128.05±26.50), P< 0.05). (2)The Cronbach′s α coefficient for DACOBS-C was calculated to be 0.92,it was used as a measure of internal consistency. The Cronbach′s α coefficients for 7 subscales of DACOBS-C ranged from 0.66 to 0.81. The factor-total correlation coefficients ranged from 0.53 to 0.68. The correlation coefficients among subscales ranged from 0.30 to 0.63. Conclusion The DACOBS-C has good psychometric properties with adequate reliability and validity, and could be applied to assess the cognitive biases of schizophrenia in China. Key words: Schizophrenia; Reproducibility of results; Davos Assessment of Cognitive Biases Scale