Predictive Validity of the Mini Nutritional Assessment Short-Form for Rehabilitation Patients: A Retrospective Analysis of the Japan Rehabilitation Nutrition Database

Background: Malnutrition is associated with worse outcome in rehabilitation patients; however, appropriate malnutrition screening tools for this population have not been investigated. We examined the predictive validity of specific cut-off values of the Mini Nutritional Assessment Short-Form version 2 (MNA-SFv2) for Japanese rehabilitation patients.

Methods: This retrospective cohort study analyzed adult patients (≥ 20 years) in the Japan Rehabilitation Nutrition Database who were in convalescent rehabilitation wards after stroke or hip fracture. Patients were classified into three categories based on MNA-SFv2 original (0-7, 8-11 and 12-14 points, respectively) or modified (0-5, 6-7 and 8-14 points, respectively) cut-off values: malnutrition, at risk of malnutrition or well-nourished. Functional independence measure (FIM) and home discharge were compared between the categories.

Results: Overall, 489 patients were analyzed. Based on the MNA-SFv2 original and modified cut-off values, 64.4% and 36.0% were malnourished, 32.3% and 28.4% were at risk of malnutrition, and 3.3% and 35.6% were well-nourished, respectively. Malnutrition defined by both cut-off values was significantly associated with the FIM at admission, whereas only those defined by modified cut-off values predicted the FIM at discharge (B, -7.1; 95% confidence interval = -12.3 to -1.9). Neither original, nor modified cut-off values predicted discharge to home and long-term care facilities.

Conclusions: An MNA-SFv2 score of 0-5 points may be useful to identify Japanese patients with poor outcomes in a rehabilitation setting.