An extended version of the MNA-SF increases sensitivity in identifying malnutrition among community living older adults. Results from the PRONUTRISENIOR project

Abstract

Background & aims: The Mini Nutritional Assessment (MNA) is the most used tool to assess malnutrition and/or its risk among older adults. Its Screening section was proposed as a short form (MNA-SF) but studies comparing the two forms present controversial results. Our main aims were to study the agreement between MNA-SF and its full form (MNA-FF) among Portuguese older adults living in the community and to develop a more sensible version of the MNA-SF.

Material and methods: This cross-sectional study used a convenience sample of 456 older adults (54.2% females) aged 65-92 years (mean = 73; SD = 6). Data analyzed included: nutritional status (MNA), social support (Fillenbaum's Social Network Index), level of independency in daily activities (Lawton e Brody's scale) and eating-related quality of life. Both MNA-FF and MNA-SF classify participants as malnourished, at risk of malnutrition or with normal nutrition status. Anthropometric assessments (weight, height, arm and calf perimeters) were carried out and BMI was computed.

Results: The agreement between the two classifications is 82.7%, but Cohen's k shows a weak agreement (weighted Cohen's k = 0.497; p < 0,001), and the sensitivity of the MNA-SF to detect malnutrition or its risk (as assessed by the MNA-FF) was 42.6% (despite a specificity of 98.8%). Participants classified as normal using the MNA-SF despite at risk using the MNA-FF present lower scores in two items from the Assessment section (number of full meals eaten daily and amount of fluid consumed per day). These were included in MNA-SF to obtain an extended short-version (MNA-SF8). The difference between the ROC curves for MNA-SF and MNA-SF8 justifies the preferential use of the MNA-SF8 with an estimated cut-off of 14 points, which showed high sensitivity (91.8%) and specificity (79.9%).

Conclusions: The addition of two items to the MNA-SF provides a more sensible tool to detect the risk of malnutrition among older adults. General eating-related questions seem relevant to assess malnutrition in this age group.

Keywords: Malnutrition; Mini nutritional assessment; Older adults; Risk of malnutrition; Sensitivity; Underestimation.