Background: The Malnutrition Screening Tool (MST) is a valid nutrition screening tool in the acute hospital setting but has not been assessed in residential aged care facilities. The aim of this secondary analysis was to determine whether the MST could be a useful nutrition screening tool when compared with a full nutrition assessment by Subjective Global Assessment (SGA) in the residential aged care setting.

Methods: Two hundred and eighty-five residents (29% male; mean age 84 ± 9 years) from eight residential aged care facilities in Australia participated in the study. A secondary analysis of data collected during a nutrition intervention study was conducted. The MST consists of two questions related to recent weight loss and appetite. Although the MST was not specifically applied, weight loss and appetite information was available and an estimated MST score (0–5) was calculated. Nutritional status was assessed by a research assistant trained in using the SGA.

Results: Malnutrition prevalence was 42.8% (122 malnourished out of 285 residents). Compared to the SGA, the MST was an effective predictor of nutritional risk (sensitivity = 83.6%, specificity = 65.6%, positive predictive value = 0.65, negative predictive value = 0.84).

Conclusions: The components of the MST have acceptable sensitivity and specificity, suggesting that it can play a valuable role in quickly identifying the risk of malnutrition in the residential aged care setting. Further prospective research using the MST tool against a broader array of objective and subjective nutritional parameters is required to confirm its validity as a screening tool in aged care settings.