Navegando por Palavras-chave "PANSS"

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    Estrutura fatorial da escala de Síndromes Positiva e Negativa (PANSS) no Brasil: validação convergente da versão brasileira
    (Universidade Federal de São Paulo (UNIFESP), 2015-03-25) Higuchi, Cinthia Hiroko [UNIFESP]; Araripe Neto, Ary Gadelha de Alencar [UNIFESP]; http://lattes.cnpq.br/8107200180236710; http://lattes.cnpq.br/9547855731878287; Universidade Federal de São Paulo (UNIFESP)
    A Escala das Síndromes Positiva e Negativa (PANSS) para esquizofrenia é uns dos instrumentos mais utilizados no Brasil. No entanto, não há estudo de validação. Objetivo: Analisar a estrutura fatorial da versão brasileira da PANSS e compará-la com a de outros países/ populações a fim de gerar dados para validação convergente. Método: A amostra foi composta por 292 pacientes diagnosticados com esquizofrenia de acordo com os critérios do Manual Diagnóstico e Estatístico de Transtornos Mentais ? quarta edição (DSM-IV), confirmados através da Entrevista Clínica Estruturada para Transtornos do Eixo I (SCID-I), aplicada por entrevistadores treinados. A estrutura fatorial foi analisada por meio da análise fatorial utilizando o método de extração de componentes principais com rotação equamax. Cargas fatoriais acima de 0,5 foram analisadas para identificação dos fatores. A consistência interna dos fatores foi avaliada por Alfa de Cronbach. Resultados: O teste Kaiser?Meyer?Olkin foi de 0,873, considerado adequado para a realização da análise fatorial. O modelo final explica 58,44% da variância total e é composto por cinco fatores: positivo, negativo, desorganização/cognição, euforia e depressão/ ansiedade. Conclusão: O modelo é semelhante quanto a composição dos fatores em relação à maioria dos outros países. As medidas de adequação do modelo e proporção da variância total explicada também são semelhantes. Os nossos dados indicam que a estrutura fatorial da versão brasileira da PANSS é similar à encontrada em outros países, o que sugere uma validação convergente da escala.
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    Explorando novas abordagens para compreensão da heterogeneidade clínica da esquizofrenia por meio da modelagem de equações estruturais
    (Universidade Federal de São Paulo (UNIFESP), 2019-04-26) Higuchi, Cinthia Hiroko [UNIFESP]; Araripe Neto, Ary Gadelha De Alencar [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Introduction: Schizophrenia is a heterogeneous disease clinically, therapeutically and biologically. This scenario is considered one of the greatest challenges to achieve real transformation in the field. Current proposals to reduce heterogeneity attempt to delimit dimensions, subtypes, or models of clinical staging. However, these models, for the most part, do not reach psychometric validity (dimensional models), do not have robust biological validation (classical subtypes or staging) or, still, do not reach greater clinical utility than the current constructs. We will use techniques based on the structural equation modeling to evaluate the Positive and Negative Syndromes Scale (PANSS) items. This instrument is widely used and address the possibilities of clinical presentation of schizophrenia. Objective: To explore the potential of PANSS to generate dimensions of symptoms and subgroups of patients with schizophrenia through models with psychometric validity (clinical models) and biological models (neuroimaging biomarkers) generated by structural equation modelling. Specific objectives: Study 1: a) To identify the best 5-factor dimensional model of PANSS; b) To evaluate the impact of clinical staging and other clinical variables in PANSS dimensions. Study 2: a) To use the PANSS as generator of more homogeneous groups regarding the profile of symptoms through a latent class analysis (LCA); b) Validate the final model of classes with external and biological variables (cortical thickness). Methods: Data from 700 patients diagnosed with schizophrenia from four different centers were analyzed. Study 1: CFA models were compared with Bayesian CFA, the latter considered to be more flexible. The multilevel structure was then included. In addition, Multiple Indicators Multiple Causes (MIMIC) modeling evaluated the impact of clinical staging of schizophrenia on the formation of factor mean. Study 2: The best LCA model was chosen based on the comparison of AIC, BIC and Log likelihood values and according to the evaluation of the items probabilities of response applied to the clinical utility of the model. The LCA derived class variable was used in univariate general linear models (GLM) to verify its effect on the cortical thickness of 143 patients, xi controlling the result for sex and age. The frontal and temporal regions of cortical thickness were selected according to the Desikan-Killiany atlas. The p-values were corrected for multiple comparisons (FDR and bonferroni). Results: Study 1: the PANSS CFA factorial solution achieves good fit indices when a multilevel structure is added. The clinical staging of schizophrenia can predict a higher mean of the factors according to the stage of the disease. Study 2: The six-class model best represents patient profiles. The class variable has effect on the cortical thickness of two regions: right superior temporal gyrus (pvalue = 0.012) and right temporal pole (p-value = 0.007), but such p-values did not remain significant after correction by multiple comparisons. Conclusions: The final models have psychometric validity and present: 1) The best dimensional model of PANSS is the CFA with multilevel structure; 2) There is impact of clinical staging in the formation of PANSS mean factors; 3) The sixclass model of PANSS indicated more homogeneous groups that indicate relation to measurements of cortical thickness in temporal regions.
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    Invariância longitudinal da dimensão negativa da PANSS no primeiro episódio de esquizofrenia
    (Universidade Federal de São Paulo (UNIFESP), 2020-10-19) Kagan, Simao [UNIFESP]; Araripe Neto, Ary Gadelha De Alencar [UNIFESP]; Universidade Federal de São Paulo
    Longitudinal invariance refers to scales stability when measured at different times for the same population. Lack of invariance means the scale itself may vary over time, not reflecting patient’s symptoms, but due to other sources of variation. The Positive and Negative Syndrome Scale (PANSS) is widely used to evaluate the evolution of schizophrenia symptoms at the beginning of the psychotic condition. On the other hand, to the best of our knowledge, longitudinal invariance has never been tested in a first-episode sample. In this study, we evaluated the longitudinal invariance of the negative dimension of the PANSS in a sample of first episode schizophrenia. Our study was conducted in a specialized early intervention service with 138 drug-naïve patients, and data was collected at two time-points: baseline and after 10 weeks. Two distinct models were tested: a unidimensional and another with two-correlated factors (diminished expression and amotivational). Only the unidimensional model met criteria for partial longitudinal invariance. Our study supports using the unidimensional model of the PANSS to assess longitudinal changes in negative symptoms after the first-episode of schizophrenia.