Population-Specific Short-Form Mini Nutritional Assessment with Body Mass Index or Calf Circumference Can Predict Risk of Malnutrition in Community-Living or Institutionalized Elderly People in Taiwan

Abstract

A simple, reliable, noninvasive, and easy-to-use instrument is important for successful monitoring of emerging nutrition problems in elderly people. The objectives of this study were to determine whether adoption of population-specific body mass index (BMI) cutpoints would improve the predictive ability of the short-form Mini Nutritional Assessment (MNA) and whether calf circumference could be an acceptable alternative to BMI in the short-form MNA without compromising its predictive ability. Using convenience sampling, the study recruited 301 community-living, 109 care center–living, and 68 nursing home–living elderly people, 65 years or older, as subjects. Subjects were evaluated with the short-form MNA in three versions: (a) the original, (b) Taiwan version 1 (T1), that adopted population-specific BMI cutpoints, and (c) Taiwan version 2 (T2), which substituted calf circumference for BMI, and with the long-form MNA-T2 as a reference. The ability of the short forms to predict the long-form MNA-T2 was evaluated with binary classification and analysis of receiver operating characteristic curves. Results were analyzed with an SPSS for Windows 12.0 software package (version 12.0.1C, 2000, SPSS Inc, Chicago, IL). Results showed that adoption of population-specific anthropometric BMI cutpoints improved the predictive ability of the short-form MNA, whereas replacement of BMI with calf circumference further improved the predictive ability of the scale (kappa values of the binary classification tests were 0.596, 0.742, and 0.843 for community-living; 0.560, 0.683, and 0.839 for care center–living; and 0.346, 0.454, and 0.522 for nursing home–living elderly for the original, T1, and T2 MNA short-form versions, respectively). These results suggest that modification of a measurement tool according to cultural or anthropometric features of the target population is necessary. The study also shows that calf circumference can be an acceptable alternative to BMI in the short-form MNA. Because measuring calf circumference is easier and less time-consuming then measuring BMI, the modified tool can make periodic nutritional screening an easier job and routine nutritional screening a more realistic goal in geriatric care.