[Psychometric properties of the Internet Addiction Test in students in Montes Claros, Minas Gerais State, Brazil].

The study aimed to assess the psychometric properties of the Brazilian Portuguese version of the Internet Addiction Test (IAT) in students. The methodological study population consisted of secondary and university students from Montes Claros, Minas Gerais State, Brazil. The following parameters were assessed: psychometric sensitivity, construct validity (factor, convergent, discriminant, and test of hypothesis), criterion validity (concurrent), and reliability (internal consistency and reproducibility). A total of 2,519 students participated, 29.6% of whom were secondary school enrollees. A three-factor measurement model was adjusted ("emotional and cognitive preoccupation with the Internet", "problems in managing time", and "performance problems"), which obtained satisfactory adequacy indices and stable structure in the independent subsamples. Convergent validity was close to the recommended level (mean extracted variation = 0.32, 0.41, and 0.45 and compound reliability values = 0.84, 0.81, and 0.71), and discriminant and concurrent validities were adequate. Internal consistency was adequate (alpha = 0.906), as was reproducibility (kappa = 0.73 and intraclass correlation coefficient = 0.90). The Portuguese-language version of the IAT presented satisfactory levels of validity, reliability, and stability in independent samples of students.