Multicentre Prospective Study on the Diagnostic and Prognostic Validity of Malnutrition Assessment Tools in Surgery
Academic Background
Malnutrition is a significant risk factor for postoperative complications, particularly in patients undergoing major abdominal surgery, where the incidence of malnutrition is high. However, there is currently no widely accepted tool for assessing malnutrition. Existing nutritional screening tools vary greatly in sensitivity and specificity, and their effectiveness across different medical centers is inconsistent. Therefore, identifying a nutritional screening tool with high diagnostic and prognostic validity in surgical patients is crucial for optimizing perioperative management and improving patient outcomes.
This study aims to evaluate the diagnostic and prognostic validity of eight commonly used nutritional screening tools in patients undergoing major abdominal surgery through a multicenter prospective cohort study and to determine the most effective screening tool. The main questions addressed include: How accurate are these tools in diagnosing malnutrition? Can they effectively predict postoperative complications and mortality? Are there significant differences in their application across different medical centers?
Source of the Paper
This paper was co-authored by scholars from multiple hospitals in Greece and Cyprus, with Georgia Petra and Evangelos I. Kritsotakis as the primary authors. The research team is affiliated with institutions such as the University of Crete, University of Cyprus, and National and Kapodistrian University of Athens. The paper was published in 2025 in the British Journal of Surgery (BJS) under the title “Multicentre prospective study on the diagnostic and prognostic validity of malnutrition assessment tools in surgery.”
Research Process
Study Design
This study is a multicenter prospective cohort study that included consecutive patients undergoing major abdominal surgery at 12 hospitals in Greece between January 2022 and December 2023. A total of 1,649 patients were enrolled, with surgical types including colorectal surgery (58%), upper gastrointestinal surgery (21%), and hepatobiliary surgery (14%). Patients unable to provide nutritional history or informed consent were excluded.
Nutritional Assessment
The study used the Subjective Global Assessment (SGA) as the reference standard for diagnosing malnutrition. SGA was completed by trained surgical registrars within 72 hours before surgery, assessing factors such as weight change, dietary intake, gastrointestinal symptoms, and functional status. Additionally, eight nutritional screening tools were applied, including GLIM (Global Leadership Initiative on Malnutrition), MNA-SF (Mini Nutrition Assessment Short Form), MST (Malnutrition Screening Tool), MUST (Malnutrition Universal Screening Tool), NRI (Nutritional Risk Index), NRS-2002 (Nutrition Risk Scale 2002), PONS (Perioperative Nutrition Screen), and SNAQ (Short Nutrition Assessment Questionnaire).
Data Analysis
The study comprehensively evaluated the nutritional screening tools through measures of diagnostic accuracy (sensitivity, specificity, diagnostic odds ratio, area under the receiver operating characteristic curve—AUC), construct validity (convergent associations with relevant variables), and prognostic validity (logistic regression). A random-effects model was used to assess heterogeneity across different medical centers.
Main Results
Incidence of Malnutrition
According to the SGA criteria, 562 out of 1,649 patients (34.1%) were diagnosed with malnutrition, of which 54 were severely malnourished. The risk of malnutrition assessed by different nutritional screening tools varied significantly, with NRS-2002 showing the lowest risk (24.0%) and MNA-SF the highest (58.6%).
Diagnostic Accuracy
In binary classification, MNA-SF had the highest diagnostic odds ratio (OR = 30.2), but its specificity was low. MUST showed the most balanced performance in sensitivity and specificity, both close to 80%. On the original ordinal scale, MNA-SF (AUC = 0.83) and MUST (AUC = 0.79) had the best discriminatory ability, with minimal heterogeneity across medical centers.
Construct and Prognostic Validity
Most nutritional screening tools performed well in construct validity, effectively identifying medical, physical, and functional variables associated with malnutrition. In terms of prognostic validity, patients classified as severely malnourished by SGA had significantly higher odds of serious 30-day postoperative complications (OR = 4.71) and in-hospital mortality (OR = 8.16). NRS-2002, MUST, and NRI also demonstrated good prognostic validity in predicting postoperative complications and mortality.
Conclusion
This study supports the use of MUST as the most effective nutritional screening tool for patients undergoing major abdominal surgery. MUST excelled in diagnostic accuracy, construct validity, and prognostic validity, with consistent application across different medical centers. The study recommends the adoption of MUST as the preferred tool for malnutrition screening in guidelines to improve perioperative management and surgical outcomes, as well as to enhance data comparability across medical centers.
Research Highlights
- Multicenter Prospective Design: Conducted across 12 hospitals with a large sample size, ensuring high external validity.
- Comprehensive Evaluation of Multiple Screening Tools: Assessed eight commonly used tools, providing a robust basis for clinical decision-making.
- Superiority of MUST: MUST demonstrated the best performance in diagnosis and prognosis, making it the recommended tool.
- Heterogeneity Analysis: Evaluated heterogeneity across medical centers using a random-effects model, offering important insights for tool application.
Research Value
This study provides scientific evidence for malnutrition screening in patients undergoing major abdominal surgery, identifying MUST as the most effective screening tool. The findings contribute to optimizing perioperative management, improving patient outcomes, and enhancing data comparability across medical centers. Future research could further explore standardized malnutrition management strategies based on MUST and assess their impact on long-term outcomes.