Scholarship of Discovery
Health literacy has emerged as an area of increasing research focus in the medical literature, yet it has received little attention in the nutrition literature. Registered dietitians (RDs) should be concerned about low health literacy considering its associations with decreased knowledge of disease and management, increased hospitalizations, decreased use of preventive care services, and increased cost of health care. Thus, this research attempts to apply the concept of health literacy into the context of nutrition.
Investigation into whether RDs screen for health literacy and/or adjust teaching methods for different level learners revealed that 79.2% (n=99) of RDs surveyed (n=125) did not use a health literacy assessment instrument. This lack of instrument use may be explained by the lack of health literacy instruments for use in nutrition education settings. Identification instruments, such as the Rapid Estimate of Adult Literacy in Medicine (REALM), the Test of Functional Health Literacy in Adults (TOFHLA), and the Newest Vital Sign (NVS) can provide the RD with an understanding of an individual’s print literacy and/or numeracy, but do not provide an understanding of additional knowledge or skills specific to nutrition.
We sought the help of RDs to determine what skills and/or knowledge are necessary for effective nutrition education in order to incorporate these ideas into an instrument specific to nutrition. Our study involved targeted interviews (n=8) that indicated that the skills required for nutrition education are dependent upon the type of diet instruction. Conceptual skills for macronutrients were important for diabetes (n=5), as well as basic math (n=4 yes; 2=depends) and portion sizes (n=4 yes; 2=depends). Knowledge of MyPyramid/food groups yielded mixed results (n=3 yes; 2=depends, 2=no; 1=no response). In addition, four indicated that all prompted components (macronutrient knowledge, food group knowledge, basic math skills, and competency with household measurements) were important. Unprompted comments indicated that diet and disease/health concepts were important (n=4) as well as knowledge of food composition/ingredients (n=3).
Consequently, we developed the Nutrition Literacy Assessment Instrument (NLAI), an original instrument containing an algorithm to direct the RD to assess only the skills or knowledge areas that the client requires education, and items intending to measure an individual’s skill or knowledge in the areas aforementioned. Items included in the NLAI were based on literature review and our targeted interviews. The NLAI was pilot-tested against the REALM with RDs and their clients and was critiqued separately by a group of RDs online.
Preliminary data from the pilot study (n=21) indicated that print literacy and nutrition literacy are different constructs, where 91% scored in the highest range of the REALM (at or above 9th grade reading) but only 62% achieved adequate nutrition literacy in all scored areas of the NLAI. The pilot also indicates 38% agreement between subjective and objective RD (n=3) measures of nutrition literacy, suggesting discrepancy between the perception of the RD and the client’s tested abilities. Significant research barriers were encountered for RDs to participate in research as a part of this pilot study, but proposed changes by the Department of Health and Human Services to the “Common Rule” may lesson this barrier in the future.
Content and face validity were established for the NLAI via a second survey of RDs when compared with the following scale: “average agreement at or above 70% is necessary, above 80% is adequate, and above 90% is good,” (House, House & Campbell, 1981). Agreement for inclusion of all sections of the instrument was reached including the Algorithm (81.8%), “Nutrition and Health” (80.9%), “Macronutrients” (87.1%), “Household Food Measurement” (94.5%), and “Food Groups” (90.7%). Additionally, a majority (79.9%) preferred the NLAI over the REALM as a measure of nutrition literacy. Future research efforts will seek to establish construct validity and reliability for the NLAI.
Gibbs, Heather Diane, "Nutrition Literacy: Foundations and Development of an Instrument for Assessment" (2012). Faculty Scholarship – Family and Consumer Science. 1.