Validity and reliability of the Brazilian Portuguese version of the BACS (Brief Assessment of Cognition in Schizophrenia).

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.

Validity and reliability of the Brazilian Portuguese version of the BACS (Brief Assessment of Cognition in Schizophrenia)

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. .

How specific are negative symptoms and cognitive impairment in schizophrenia? An analysis of PANSS and SCoRS.

INTRODUCTION: Interview-based scales can be used as coprimary measures to complement the assessment of cognitive impairment in schizophrenia. One major question that arises from the use of such tools is how specific they are in relation to other psychopathological domains. We analyse the specificity of the Positive and Negative Syndrome Scale (PANSS) negative subscale and the Schizophrenia Cognition Rating Scale (SCoRS). METHODS: We performed a principal component analysis (PCA) of PANSS negative subscale, rated by the interviewer, and SCoRS ratings from three different sources (patient, informant, and interviewer) in 101 patients with schizophrenia. Additionally, we correlated mean SCoRS ratings to PANSS negative subscale items to determine whether any PANSS item is particularly related to cognition. RESULTS: The PCA showed that the two first components, which explained approximately 40% of the total variance of the scales, represent the SCoRS ratings and the PANSS negative subscale ratings, respectively. The mean interviewer SCoRS was significantly correlated with the PANSS negative Item 5 (difficulty in abstract thinking) and with the mean PANSS negative subscale. The latter correlation was no longer significant when "difficulty in abstract thinking" was eliminated from PANSS negative subscale. CONCLUSIONS: In general, SCoRS and PANSS negative subscale scores address different constructs; however, the PANSS negative item "difficulty in abstract thinking" seems to address a cognitive dimension.

Sensitivity and applicability of the Brazilian version of the Brief Assessment of Cognition in Schizophrenia (BACS).

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±8.4minutes 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.

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±8.4minutos 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.