Evaluation of the Mini Nutritional Assessment in the elderly, Tehran, Iran
Objective: To determine whether the Mini Nutritional Assessment (MNA) can screen and diagnose for malnutrition in the Iranian elderly. Design: The MNA was administered to all volunteers. Each patient underwent anthropometric and serum albumin measurements. Reliability, validity, sensitivity, specificity, positive-and negative-predictive values were estimated. To identify optimal threshold values for predicting malnutrition, receiver-operating characteristic curve analysis was performed for MNA scores. Setting: Kahrizak Charity Foundation (Tehran, Iran). Subjects: Two hundred and twenty-one consecutive elderly patients entered into the cross-sectional study. Amputees and patients with liver or renal disorders, oedema or any end-stage diseases were excluded. Results: According to MNA score, 3.2% were malnourished, 43.4% were at risk of malnutrition and 53.4% were well nourished. The proportions in these categories according to ideal body weight and serum albumin were 2.3%, 17.1% and 80.6%, respectively. Cronbach's alpha coefficient (reliability) was 0.61. The correlations between total MNA score, anthropometric values and serum albumin (criterion-related validity) were all significant. There were significant differences in total MNA score between two BMI groups but not between two categories according to serum albumin and skin ulcers (construct validity). The sensitivity and specificity of the MNA according to its established cut-off points were 82% and 63%, respectively. Positive-predictive value was 35% and negative-predictive value was 93%. By using the best cut-off point (MNA score of 22 according to Youden index), the sensitivity, specificity, positive-predictive value and negative-predictive value were 88%, 62%, 57% and 89%, respectively. Conclusions: The MNA with its established cut-off points may not be a good fit for Asian populations, including Iranian elderly.