Psychometric validation of an instrument to assess undergraduate nursing student's knowledge of the aetiology, prevention and treatment of venous leg ulcers

In the management of individuals with venous leg ulcers, education serves as a pivotal tool for acquiring knowledge, fostering appropriate attitudes, and promoting best practices. Consequently, assessing knowledge, skills, attitudes, confidence, and commitment becomes essential, necessitating the development of suitable evaluation instruments. Pre- and post-test assessments align with Level 2 of Kirkpatrick's model. Moreover, nurse educators should integrate assessment into the teaching-learning sequences. To psychometrically validate an instrument designed to assess undergraduate nursing students' knowledge of the aetiology, prevention, and treatment of venous leg ulcers. A multi-phase study was designed to develop the tool and subsequently validate its psychometric properties. The study was conducted at three sites within the University of the Basque Country and one site within the University of Alicante. A total of 516 students from all four years of the nursing degree program participated. The construct definition and instrument development were previously published. This article presents the psychometric evaluation, which involved classical item analysis, analysis of psychometric properties according to the Rasch model, differential item functioning analysis, construct validity analysis through hypothesis testing in known groups, and reliability analysis via internal consistency. The results validated the Knowledge on Venous Leg Ulcer Questionnaire, reducing it from 72 initial items to 36 definitive items. It was found to be a valid and reliable instrument, capable of detecting statistically significant differences between known groups. Knowledge scores on a 0–100 scale were found to be 33.1 (SD = 19.5) for the first-second year groups, and 48.3 (SD = 17.5) for the third-fourth year groups, demonstrating a progressive and logical increase in knowledge each year. The Knowledge on Venous Leg Ulcer Questionnaire appears to be a valid and reliable instrument for measuring nursing students' knowledge of venous leg ulcers. However, further research in different contexts is required to confirm these results.