Developing a novel measurement of nutrition literacy

INTRODUCTION: While health literacy (HL) measurement has received some attention, tools for assessing HL do not adequately measure nutrition literacy (NL). NL is critical to manage many chronic disease prevention/management programs. The objective of this multi-stage research was to develop a NL-specific instrument and to determine the need for an objective measure. METHODS: Key informant interviews (n=8) yielded 5 skill/ knowledge domains specific to NL that were incorporated into the Nutrition Literacy Assessment Instrument (NLAI). Registered dietitians (RDs) (n=134-178) responded online (SurveyGizmo) to a 35-item survey to establish NLAI content validity. For each construct, 70% agreement in responses was necessary; 80% and 90% agreement were considered “adequate” and “good”, respectively. Comments were analyzed using content analysis. The NLAI was pilot-tested against the Rapid Estimate of Adult Literacy in Medicine (REALM) with RDs (n=5) and their clients (n=26). Comparisons were made between RD subjective assessments, REALM and NLAI. RESULTS: RDs agreed that all NLAI sections accomplished their purpose, with “adequate” agreement (81%) on average (content validity). In the pilot, no significant correlation (r=0.378) was found between the REALM and NLAI; subjective RD assessment and NLAI did not agree 44% of the time. CONCLUSIONS: The NLAI is a face and content valid measure of NL. Lack of correlation between the REALM and the NLAI confirms that health literacy and NL are different constructs. Discrepancy between the RDs' subjective assessment and tested abilities supports the need for an objective measure. Future research is needed to estimate construct validity and reliability for the NLAI.