RESUMO
PURPOSE: Questionnaires are indispensable tools in epidemiologic studies and clinical surveys. Many questionnaires focusing on sleep disorders have been described in the literature. This cross-sectional study is aimed to assess the consistency and reliability of the Brazilian Portuguese Version of the Mini-Sleep Questionnaire (MSQ-BR). METHODS: Self-administered questionnaires were given to a sample of 1,108 undergraduate students. The variables collected were age, gender, socioeconomic level, and MSQ-BR scores. A subgroup of 53 students was randomly chosen to test the test-retest reliability of the instrument. Internal consistency of total MSQ-BR and its subscales (i.e., insomnia and hypersomnia) was evaluated using Cronbach's alpha coefficient. RESULTS: Our results showed good internal consistency of total MSQ-BR score, with a Cronbach's alpha value of 0.770. The insomnia subscale had an adequate internal consistency (Cronbach's alpha, 0.749). On the other hand, the hypersomnia subscale had moderate internal consistency (Cronbach's alpha, 0.624). The test-retest analysis showed good reliability of the instrument using Pearson's correlation coefficient. CONCLUSIONS: The MSQ-BR has adequate internal consistency and test-retest reliability. The MSQ-BR insomnia has adequate internal consistency for use as a separate application. However, the MSQ-BR hypersomnia demonstrated only moderate internal consistency for use as a separate application. Our intention was not to introduce modifications to the questionnaire, but to evaluate the reliability of total MSQ-BR and its subscales. Others studies are needed to assess the consistency of MSQ compared to other instruments.