ANÁLISE DAS PROPRIEDADES PSICOMÉTRICAS DO INSTRUMENTO ALCOHOL USE DISORDERS IDENTIFICATION TEST POR MEIO DA TEORIA DE RESPOSTA AO ITEM.

Abstract

INTRODUCTION: The Item Response Theory (IRT), by means of mathematical models, has been used to analyze the psychometric properties of instruments in the health area. Alcohol use has been considered a serious public health problem, besides being the most consumed psychoactive substance worldwide, and its use usually begins in adolescence. This consumption can be measured by instruments consisting of representative items, such as the Alcohol Use Disorders Identification Test (AUDIT). Therefore, assessing the psychometric properties of this instrument as well as the item parameters and latent trait levels provides important information to characterize alcohol consumption in the study population. OBJECTIVE: To analyze the psychometric properties of AUDIT and the creation of a measurement scale to estimate the level of alcohol consumption in an adolescent population by means of Item Response Theory. MATERIAL AND METHODS: Cross-sectional study formed by 1,002 adolescents between 18 and 19 years old born in São Luís-MA. First, using confirmatory factor analysis, we evaluated the factorial structure of AUDIT composed by ten items. In order to build the scale for measuring the level of alcohol consumption in the sample under study, different one-dimensional TRI models were adjusted for polytomic items. The dimensionality study was performed on the polycoric correlation matrix based on the analysis of main components and Rackase criteria. Different model fitting criteria were considered: TFI (Tucker-Lewis Index), CFI (Comparative Fix Index), RMSEA (Root Mean Square Error of Approximation). The model selection was based on the AIC (Akaike Information Criterion) and BIC (Bayesian Information Criterion) criteria. RESULTS: The findings of this study showed a predominance of 18-year-old adolescents (66.9%), most female 569 (56.8%), brown/mulatto 634 (63.3%). The alpha coefficient of Cronbach=0.7039, omega of Macdonald=0.76 and KMO=0.79 and confirmed the unidimensionality by the Rackase criteria. The item "How often do you consume six or more drinks in a single occasion?” showed greater power of discrimination. The measurement scale for the alcohol consumption level was composed by three anchor levels. In the first level were adolescents who took six or more doses on a single occasion, less than once a month. In the second level were the adolescents who, when drinking, consumed from 3 to 4 doses in a single occasion at least once a month or less, however they could consume up to six or more doses in some situation. Finally, at the last level, there were adolescents who, when drinking, could take 7 to 9 doses. CONCLUSION: The findings of this study allowed the construction of a scale from Item Response Theory to measure the level of alcohol consumption among the study participants.