Rasch analysis implementation in nursing research: A methodological approach.

The design and validation of tools constitutes a fundamental pillar of nursing research, where it is essential to incorporate the most current methodologies and analyses in order to guarantee validity and reliability in their clinical application. The aim of this paper is to describe the characteristics of the Rasch analysis and the methodology for its development as well as to discuss its relevance and applicability in nursing research, highlighting its potential contribution to the improvement of the quality and accuracy of measurement instruments in the discipline. Through a narrative synthesis, the theoretical foundations of Rasch analysis are described and the characteristics and assumptions that must be fulfilled to carry out this type of analysis are presented. Subsequently, the implementation methodology is presented in 11 steps: definition of objectives and preparation, instrument design, data collection, initial and unidimensionality analysis, goodness-of-fit assessment (infit-outfit, reliability and separation), item local independence assessment (Yen's Q3 coefficient), item calibration and estimation of skills, measurement invariance analysis (DIF analysis), review and modification of the instrument, final analysis and validation, interpretation of results. Examples of use are presented, as well as the advantages and limitations of the method. In conclusion, the Rasch analysis provides a valuable methodology for the evaluation of clinical competencies and skills, as well as for the development and validation of measurement instruments of great utility for research in care, although it would be necessary to promote training and standardization in its use.