RESUMEN
ABSTRACT Objective: To develop, adapt and validate an instrument named "CSII - Brazil" to assess users' conceptual and procedural knowledge of continuous subcutaneous insulin infusion systems. Materials and methods: Methodological and exploratory study developed in three stages: a) instrument development; b) content validation and cultural adaptation (evaluation by a committee of experts and pre-test with CSII users); c) psychometric validation through instrument application in a sample of 60 patients by means of the web tool e-Surv. Internal consistency and reproducibility analyses were performed within IBM SPSS Statistics 20 programming environment. Results: The 16 multiple-choice question instrument successfully attained a content validity index of 0.97, showing satisfactory internal consistency, with 0.61 Cronbach's alpha [95% CI 0.462-0.746] and an intraclass correlation coefficient of 0.869 [95% CI: 0.789-0.919] between the test and retest scores. Conclusion: The CSII - Brazil instrument is considered adequate and validated to assess continuous subcutaneous infusion system users' conceptual and procedural knowledge.