The Nutrition Literacy Assessment Instrument for Italian Subjects, NLit-IT: Exploring Validity and Reliability
Virginia Vettori, Chiara Lorini, Heather Gibbs, Francesco Sofi, Vieri Lastrucci, Gino Sartor, Ilaria Fulvi, Duccio Giorgetti, Giuseppe Cavallo, Guglielmo Bonaccorsi
Abstract
The aim of this study was to test validity and reliability of the adapted version of the Nutrition Literacy Assessment Instrument (NLit) for Italian people (NLit-IT). An observational cross-sectional study was conducted, involving a convenience sample of adults (n = 74). To explore the validity of the tool, we considered both diet quality as an outcome of NL, and health literacy (HL) as a construct that presents similarities and differences with NL. Diet quality was measured by adherence to the Mediterranean Diet (Med diet) through the validated Mediterranean Diet Literature-based adherence score (MEDI-Lite). The relationship between NL level and adherence to Med diet was assessed by linear regression analysis and computing correlations between NLit-IT and MEDI-Lite scores (Spearman’s Rho). Additionally, we evaluated the correlation between NLit-IT score and the level of HL (Spearman’s Rho). Internal consistency and reliability were measured by Cronbach’s alpha and intraclass correlation coefficient (ICC) respectively. Internal consistency (ρT = 0.78; 95% CI, 0.69–0.84) and reliability (ICC = 0.68, 95% CI, 0.46–0.85) were confirmed. In addition, NLit-IT total score was correlated with MEDI-Lite score (Rho = 0.25; p-value = 0.031) and multivariate regression analysis confirmed that NL significantly contributed to MEDI-Lite score (R2 = 0.13; β = 0.13; p-value = 0.008). There was no significant association between the level of HL and NL. In conclusion, NLit-IT showed validity and reliability as a measure of NL for Italian people.