Functional health literacy : psychometric properties of the newest vital sign for Portuguese adolescents (NVS-PTeen)

• Published in: Nutrients Vol. 13; no. 3; p. 790
• Main Authors: Santos, Osvaldo, Stefanovska-Petkovska, Miodraga, Virgolino, Ana, Miranda, Ana Cristina, Costa, Joana, Fernandes, Elisabete, Cardoso, Susana, Vaz Carneiro, António
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 27.02.2021; MDPI AG
• Subjects: Adolescents; Decision making; Functional health literacy; Health literacy; Item response theory; Numeracy; Psychometrics; Quantitative psychology; Questionnaire; Reading comprehension; Reliability analysis; Students; Teenagers; functional health literacy; psychometrics; questionnaire; item response theory; adolescents
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu13030790

Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/) Self-management of health requires skills to obtain, process, understand, and use health-related information. Assessment of adolescents’ functional health literacy requires valid, reliable, and low-burden tools. The main objective of this study was to adapt and study the psychometric properties of the Newest Vital Sign for the Portuguese adolescents’ population (NVS-PTeen). Classic psychometric indicators of reliability and validity were combined with item response theory (IRT) analyses in a cross-sectional survey, complemented with a 3-month test-retest assessment. The NVS-PTeen was self-administered to students enrolled in grades 8 to 12 (12 to 17 years old) in a school setting. Overall, 386 students (191 girls) from 16 classes of the same school participated in the study (mean age = 14.5; SD = 1.5). Internal reliability of the NVS-PTeen was α = 0.60. The NVS-PTeen total score was positively and significantly correlated with Portuguese (r = 0.28) and mathematics scores (r = 0.31), school years (r = 0.31), and age (r = 0.19). Similar to the original scale (for the U.S.), the NVS-PTeen is composed of two dimensions, reading-related literacy and numeracy. Temporal reliability is adequate, though with a learning effect. IRT analyses revealed differences in difficulty and discriminative capacity among items, all with adequate outfit and infit values. Results showed that the NVS-PTeen is valid and reliable, sensible to inter-individual educational differences, and adequate for regular screening of functional health literacy in adolescents. This research was funded by the Fundação para a Ciência e a Tecnologia (FCT), under the project Health Information of Portuguese Population: Health Knowledge & Perceived Quality and Accessibility of Health Information Sources (Reference: HMSP-IISE/SAU-ICT/0004/2009). The writing of the paper also benefited from funding from the FCT under the grants UIDB/04295/2020 and UIDP/04295/2020. This funding entity had no role in the design or writing of this artic