The use of the Mini-Nutritional Assessment (MNA) tool in elderly orthopaedic patients

Objective: To assess the use of the Mini-Nutritional Assessment (MNA) in el derly orthopaedic patients. Design: An observation study assessing the nutritional status of female ort hopaedic patients. Setting: The orthopaedic wards of the Royal Surrey County Hospital. Subjects: Forty-nine female patients aged 60-103 y; dietary records were ob tained for 41 subjects and 36 subjects gave a blood sample for biochemical analysis. Major outcome methods: MNA questionnaire, anthropometry, plasma albumin, tr ansferrin, C-reactive protein (CRP) levels and dietary analyses. Results: The group as a whole had low mean values for body weight, albumin and transferrin and high CRP levels. In addition, the group had mean energy intakes well below the estimated average requirement (EAR) and mean intake s of vitamin D, magnesium, potassium, selenium and non-starch polysaccharid es (NSP) were below the lower reference nutrient intakes (LRNI). The MNA sc reening section categorized 69% of the patients as requiring a full assessm ent (scored 11 or below), but for the purposes of the study the MNA was com pleted on all patients. The MNA assessment categorized 16% of the group as 'malnourished' (scored < 17 points), 47% as 'at risk' (scored 17.5-23.5) an d 37% as 'well nourished' (scored > 23.5). Significant differences were fou nd between the malnourished and well nourished groups for body weight (P < 0.001), body mass index (BMI) (P < 0.001), demiquet (P < 0.001) and minder (P < 0.001). Mean values for energy and nutrient intakes showed a clear ste pwise increase across the three groups for all nutrients except sodium, wit h significant differences for protein (P < 0.05), carbohydrate (P < 0.05), riboflavin (P < 0.05) niacin (P < 0.05), pyridoxine (P < 0.05), folate (P < 0.05), calcium (P < 0.05), selenium (P < 0.05), iron (P < 0.05) and NSP (P < 0.05) intakes. Stepwise multiple regression analysis indicated that anth ropometric assessments were the most predictive factors in the total MNA sc ore. The sensitivity and specificity of the MNA was assessed in comparison with albumin levels, energy intake and minder. The sensitivity of the MNA c lassification of those scoring less than 17 points in comparison with album in levels, energy intake and minder varied from 27 to 57% and the specifici ty was 66-100%. This was compared with the sensitivity and specificity of u sing a score of less than 23.5 on the MNA to predict malnourished individua ls. Using this cut-off the sensitivity ranged from 75 to 100%, but the spec ificity declined to between 37 and 50%. Conclusions: The results suggest that the MNA is a useful diagnostic tool i n the identification of elderly patients at risk from malnutrition and thos e who are malnourished in this hospital setting. Sponsorship: Nestle Clinical Nutrition, Croydon, Surrey.