[Evidence-based practice applied to diagnostic reasoning].

Nurses apply knowledge, perceptual and cognitive skills to analyze patient data and propose nursing interventions. The interventions' outcomes depend on their appropriateness which, in turn, depends on the accuracy of nurses' interpretations. The purpose of this paper is to discuss the use of evidenced-based practice (EBP) for nursing diagnostic reasoning, by means of a written case study. The principles of EBP in diagnostic reasoning are: validity of a diagnostic test; ability of a test to discriminate those who do or do not display a specific response; ability of a test to estimate the magnitude of a response; and the appropriateness of a diagnostic test within the clinical context. Gaps in nursing knowledge jeopardize the application of EBP principles in clinical nursing assessment and diagnosis. The authors present a framework to demonstrate the application of EBP to diagnostic reasoning.