Dados normativos para população brasileira de meia-idade em testes de uso frequente na clínica neuropsicológica

Abstract

INTRODUCTION: Tests are essential tools in the context of neuropsychological assessment, favoring the diagnosis of neurological disorders, such as dementias. When interpreting results obtained by patients, references are necessary in healthy people of the population to which they belong. For this purpose, normative studies are developed. People may have different performances associated with sociodemographic factors. Age and educational status have been shown to be the most influential factors. OBJECTIVES: To develop normative data for neuropsychological tests commonly used in clinical practice in middle-aged Brazilian adults and to verify the influence of education, age, sex and intelligence quotient (IQ) on the variability of the results in neuropsychological tests. METHODS: The sample consisted of 120 healthy individuals, aged between 45 and 64 years, divided into three groups by educational status (4-7, 8-11 and 12 years of schooling) and two groups by age (45 -54 and 55-64 years), in a total of six groups of 20 participants. As exclusion criteria, factors that could compromise cognitive function at the time of testing were investigated. The tests selected were the Mattis dementia rating scale, trail making test, fluency test, with semantic (animals) and phonemic (FAS) references, and the clock drawing test. In the statistics, the results were presented as mean values, standard deviations and percentiles. Educational status, age, sex and IQ were analyzed as categories, using appropriate statistical methods, according to the data distribution. Years of schooling, age and IQ were also analyzed as continuous variables, being correlated with the results in the neuropsychological tests. RESULTS: Normative data of the tests are reported in tables. They are divided in groups by age and education. Regarding the influence of the independent variables in the results, educational status influenced the differences in the results of almost all tests, with the exception of the clock drawing. In the comparison of the two age groups, differences emerged in the two parts of the trail making test and in the letter F of the fluency test. In the sex category, a difference in the fluency test letter F was found. The differences evidenced in the IQ analysis were similar to those occurred in educational status. A strong correlation was found between the independent variables years of study and IQ. CONCLUSIONS: The present study contributes to neuropsychological assessment in Brazil. It provides normative data for the middle-aged population with four or more years of schooling, in frequently used tests. It confirms findings from other studies on the strong influence of education, including in the comparison between the middle and higher levels. The influence of age was lower, since the sample is restricted to two age groups. We expect that this study to be useful to clinicians and to stimulate new normative studies in Brazil.