Comparative evaluation of nutritional risk screening tools in hospitalized children with acute gastroenteritis

Background Malnutrition is common in hospitalized children with acute gastroenteritis, yet the optimal nutritional risk screening tool for this population remains unclear. This study aimed to compare the diagnostic performance and clinical utility of STRONGkids, PYMS, and STAMP in identifying malnutrition among hospitalized children with acute gastroenteritis. Methods In this multicenter retrospective study, children hospitalized with acute gastroenteritis between January 2024 and January 2026 were identified from electronic medical records at admission. After exclusions, 855 children were included in the final analysis. Nutritional risk was retrospectively assessed using STRONGkids, PYMS, and STAMP. Nutritional status was classified according to body mass index-for-age z scores based on the World Health Organization growth reference. Receiver operating characteristic curve analysis was used to evaluate discriminatory performance, with pairwise comparisons performed using the DeLong test. Optimal cut-off values were determined using the Youden index, and decision curve analysis was performed to assess clinical utility. Results Of the 855 children included, 82 were malnourished and 773 had normal nutritional status. Compared with children with normal nutritional status, malnourished children were younger and had more vomiting and diarrhea episodes, longer hospital stay, higher screening scores, and more severe dehydration. PYMS showed the best discriminatory performance, with an AUC of 0.860 (95% CI, 0.824–0.896), followed by STAMP at 0.796 (95% CI, 0.748–0.845) and STRONGkids at 0.717 (95% CI, 0.658–0.776). PYMS performed significantly better than both STRONGkids and STAMP, and STAMP also outperformed STRONGkids. At the optimal cut-off of 3, PYMS had the highest sensitivity, specificity, Youden index, and negative predictive value. Decision curve analysis also supported the superior clinical utility of PYMS. Conclusion Among the three screening tools, PYMS demonstrated the best overall performance for identifying malnutrition in hospitalized children with acute gastroenteritis and may be the most suitable tool for early nutritional risk screening in this population.