Accuracy of Quick and Easy Undernutrition Screening Tools—Short Nutritional Assessment Questionnaire, Malnutrition Universal Screening Tool, and Modified Malnutrition Universal Screening Tool—in Patients Undergoing Cardiac Surgery

Abstract

The objective of this study was to compare the quick-and-easy undernutrition screening tools, ie, Short Nutritional Assessment Questionnaire and Malnutrition Universal Screening Tool, in patients undergoing cardiac surgery with respect to their accuracy in detecting undernutrition measured by a low-fat free mass index (FFMI; calculated as kg/m²), and secondly, to assess their association with postoperative adverse outcomes. Between February 2008 and December 2009, a single-center observational cohort study was performed (n=325). A low FFMI was set at ≤14.6 in women and ≤16.7 in men measured using bioelectrical impedance spectroscopy. To compare the accuracy of the Malnutrition Universal Screening Tool and Short Nutritional Assessment Questionnaire in detecting low FFMI sensitivity, specificity, and other accuracy test characteristics were calculated. The associations between the Malnutrition Universal Screening Tool and Short Nutritional Assessment Questionnaire and adverse outcomes were analyzed using logistic regression analyses with odds ratios and 95% confidence intervals (CI) presented. Sensitivity and receiver operator characteristic-based area under the curve to detect low FFMI were 59% and 19%, and 0.71 (95% CI: 0.60 to 0.82) and 0.56 (95% CI: 0.44 to 0.68) for the Malnutrition Universal Screening Tool and Short Nutritional Assessment Questionnaire, respectively. Accuracy of the Malnutrition Universal Screening Tool improved when age and sex were added to the nutritional screening process (sensitivity 74%, area under the curve: 0.72 [95% CI: 0.62 to 0.82]). This modified version of the Malnutrition Universal Screening Tool, but not the original Malnutrition Universal Screening Tool or Short Nutritional Assessment Questionnaire, was associated with prolonged intensive care unit and hospital stay (odds ratio: 2.1, 95% CI: 1.3 to 3.4; odds ratio: 1.6, 95% CI: 1.0 to 2.7). The accuracy to detect a low FFMI was considerably higher for the Malnutrition Universal Screening Tool than for the Short Nutritional Assessment Questionnaire, although still marginal. Further research to evaluate the modified version of the Malnutrition Universal Screening Tool, ie, the cardiac surgery–specific Malnutrition Universal Screening Tool, is needed prior to implementing.