Mini Nutritional Assessment Short-Form (MNA-SF) Predicts Clinical Outcomes: Cohort Study of Small-Sized Hospital in Japan

Background: Among the elderly, the rate of complications resulting from malnutrition is high. A mini nutritional assessment short-form (MNA-SF) was confirmed overseas to identify malnutrition and predict clinical outcomes. This study aimed to evaluate the MNA-SF usefulness in Japanese small-sized hospital. Methods: This was a prospective cohort study conducted on hospitalized patients at small-sized hospital, Department of General Internal Medicine which has 30 beds. All consecutive hospitalized patients for 4 months were included. A MNA-SF assessment on admission was implemented as exposure factor. Primary outcomes included death and complications such as infectious disease, organ failure, delirium, falls, diagnosis of malignancy and poor oral intake. Secondary outcomes including days of hospitalization and discharge rate back to home were also measured. Results: 177 patients were analyzed with the MNA-SF assessment. Twenty-three (13%) patients were "normal nutritional status", 64 (36%) were "at risk" and 90 (51%) were "malnourished". The mortality rate was 0, 1.4 and 6.9 cases/1000 person-day (incidence ratio 4.9 times), respectively. The complications incidence rate was 0, 18 and 30.1 cases/1000 person-day (incidence ratio 1.7 times), respectively. The number of days in hospital were 11.1, 14.0 and 21.6 days (p < 0.01), respectively. The discharge to home rate was 90.4, 84.4 and 53.3% (p < 0.01), respectively. Conclusions: Among all patients on a Japanese general medicine ward, those with poor nourishment assessed by the MNA-SF showed a high death rate and complication incidence rate. And they are also proved to be difficult to early discharge from the hospital back to the patient's homes.