Background and purpose: A valid and reliable assessment tool is fundamental for evaluating the knowledge of individuals about using oral anticoagulant therapy (OAT). The purpose of this study was to develop a tool to assess knowledge about OAT and provide evidence to support its use in people living in developing countries.
Methods: Construction and validation: development of items; assessment of face and content validity; pilot study; application of the instrument to a sample of 500 users of OAT to analyze dimensionality, convergent validation, and reliability.
Results: Analysis of dimensionality suggested a unidimensional instrument. Direct correlation between knowledge of OAT and educational level was confirmed (r = .61, p < .001) (validity of construct). Reliability measured by KR-20 was 0.86.
Conclusions: The new instrument was shown to be valid and reliable for assessing knowledge of OAT in the population studied.