Background and Objectives: A short version of the Brief Assessment of Cognition in Schizophrenia (BACS) was derived. Methods: We calculated the corrected item-total correlation (CITC) for each test score relative to the composite score, and then computed the proportion of variance that each test shares with the global score excluding that test (Rt² = CITCt²) and the variance explained per minute of administration time for each test (Rt²/mint). Results and Conclusions: The 3 tests with the highest Rt²/mint, Symbol Coding, Digit Sequencing, and Token Motor, were selected for the Abbreviated BACS.

OBJECTIVE: To assess the validity and reliability of the Brazilian Portuguese version of the Brief Assessment of Cognition in Schizophrenia by examining its temporal stability, internal consistency, and discriminant and convergent validity. METHODS: The Brief Assessment of Cognition in Schizophrenia was administered to 116 stable patients with schizophrenia and 58 matched control subjects. To assess concurrent validity, a subset of patients underwent a traditional neuropsychological assessment. RESULTS: The patients with schizophrenia performed significantly worse than the controls (p<0.001) on all subtests of the Brief Assessment of Cognition in Schizophrenia and on the total score, which attests to the discriminant validity of the test. The global score of the Brief Assessment of Cognition in Schizophrenia was significantly correlated with all of the subtests and with the global score for the standard battery. The Brief Assessment of Cognition in Schizophrenia also had good test-retest reliability (rho>0.8). The internal consistency of the Brief Assessment of Cognition in Schizophrenia was high (Cronbach's α ϝ 0.874). CONCLUSION: The Brazilian Portuguese version of the Brief Assessment of Cognition in Schizophrenia exhibits good reliability and discriminant and concurrent validity and is a promising tool for easily assessing cognitive impairment in schizophrenia and for comparing the performance of Brazilian patients with that of patients from other countries.

Resumo A avaliação cognitiva na esquizofrenia tem utilizado tradicionalmente baterias longas e complexas ou que variam significativamente em seu conteúdo. A "Brief Assessment of Cognition in Schizophrenia" (BACS) foi desenvolvida para cobrir os principais déficits cognitivos na esquizofrenia, para ser de fácil e breve aplicação, assim como portátil, sensível e confiável. Objetivos: Investigar a aplicabilidade e a sensibilidade da versão brasileira da BACS (Brazilian-BACS). Métodos: O desempenho de 20 pacientes estáveis com esquizofrenia na Brazilian-BACS foi comparado ao de 20 controles saudáveis pareados. Resultados: A aplicação da Brazilian-BACS exigiu 43.4±8.4 minutos nos pacientes e 40.5±5.7 minutos nos controles (p=0.17). Todos os testes foram significativamente diferentes entre pacientes e controles (P<0.01). A correlação de Pearson e o alfa de Cronbach evidenciaram alto grau de consistência interna no desempenho dos pacientes. O déficit cognitivo nos pacientes foi cerca de 1,5 desvio-padrão menor do que nos controles. Esses resultados são consistentes com os relatados na validação da versão original e em meta-análises de estudos similares. Conclusões: A Brazilian-BACS mostrou boas aplicabilidade e sensibilidade na investigação dos principais domínios cognitivos comprometidos na esquizofrenia. Portanto, a Brazilian-BACS mostra-se um instrumento promissor no estudo da cognição de pacientes com esquizofrenia no Brasil.

Abstract Cognitive assessment in schizophrenia has traditionally used batteries that are long and complex or differ widely in their content. The Brief Assessment of Cognition in Schizophrenia (BACS) has been developed to cover the main cognitive deficits of schizophrenia as well as to be easily and briefly administered, portable, sensitive and reliable. Objectives: To investigate the applicability and sensitivity of the Brazilian Version of the BACS (Brazilian-BACS). Methods: Performance of 20 stable patients with schizophrenia on the Brazilian-BACS was compared to 20 matched healthy controls. Results: Applying the Brazilian-BACS required 43.4±8.4 minutes for patients and 40.5±5.7 minutes for controls (p=0.17). All tests demonstrated significant differences between controls and patients (P<0.01). Pearson's correlation analysis and Cronbach's a evidenced a high internal consistency for patient performance. The cognitive deficit in the patients was approximately 1.5 standard deviations below controls. These results were consistent with those reported in the validation of the original version and in meta-analyses of similar studies. Conclusions: The Brazilian-BACS displayed good applicability and sensitivity in assessing the major cognitive constructs that are impaired in schizophrenia. Thus, the Brazilian-BACS seems to be a promising tool for assessing cognition in patients with schizophrenia in Brazil.