Can the Mini Nutritional Assessment (MNA) Be Used as a Nutrition Evaluation Tool for Subacute Inpatients over an Average Length of Stay?

Abstract

The prevalence of malnutrition in subacute inpatient settings has been reported to be 30-50%. While there are a number of nutrition evaluation tools which have been validated to diagnose malnutrition, the use of a validated nutrition evaluation tool to measure changes in nutritional status during an average length of stay for a subacute inpatient has not yet been tested. This study aims to determine the potential of the full MNA (full Mini Nutritional Assessment) and MNA (Mini Nutritional Assessment Short Form) scores to measure change in nutritional status over an average subacute inpatient stay (21 days). A prospective observational study. The study was performed in three Rehabilitation and Geriatric Evaluation and Management (GEM) wards of the Kingston Centre, Monash Health, Melbourne, Australia. All patients ≥65 years admitted to these wards with an expected length of stay of at least 14 days were considered for inclusion in this study. Nutritional status was assessed on admission using the full MNA as part of usual dietetic care and patients were provided with nutrition intervention/diet therapy based on full MNA classification. Full MNA score (0-30), MNA score (0-14), anthropometry (weight and height) and nutritional biochemistry (serum albumin, transthyretin and C-reactive protein) were compared between admission and day 20.5 ± 2.4. Mean age (± SD) of 83 ± 7 years, n=114. For those patients diagnosed at risk of malnutrition or malnourished (n=103), there were significant increases in full MNA score (1.8 ± 2.4, p<0.001), MNA score (0.9 ± 1.7, p<0.001), weight (0.6 ± 2.5 kg, p=0.017) and serum albumin (1.4 ± 4.4 g/L, p=0.003) over the study period. All four of the full MNA domain sub-scores, also increased significantly in those patients diagnosed at risk of malnutrition or malnourished (n=103): anthropometric assessment (p<0.001), dietary assessment (p<0.001), general status assessment (p=0.019) and self-perceived health and nutrition states (p=0.033). Both the MNA and full MNA can be used to evaluate nutrition progress within the subacute inpatient setting over a three week time period, thereby providing clinicians with feedback on a patient's nutrition progress and assisting with ongoing care planning. Due to its ease of use and shorter time required to complete, the MNA may be the preferred nutrition evaluation tool in this setting.