Comparison of six nutritional screening tools for identifying BMI‑defined malnutrition in patients with Crohn’s disease: a cross‑sectional study

There is currently debate in clinical practice regarding the selection of nutritional screening tools for patients with Crohn’s disease. This cross-sectional study aimed to compare the ability of six nutritional screening tools to identify malnutrition defined by a body mass index (BMI) < 18.5 kg/m 2 in patients with Crohn’s disease. A total of 163 patients with Crohn’s disease admitted to the Gastroenterology Treatment Centre of a tertiary-level hospital in Nanjing from September 2023 to December 2023 were enrolled. Their nutritional status was assessed using the NRS2002, PG-SGA, MNA-SF, GLIM criteria, MUST, and bioelectrical impedance analysis (BIA). The area under the receiver operating characteristic curve (AUC) was used to evaluate the discriminative ability of the six tools for identifying BMI-defined malnutrition. Based on BMI < 18.5 kg/m 2 as the operational definition, the prevalence of malnutrition in Crohn’s disease patients was 28.83%. An enterostomy was associated with malnutrition. All six tools showed significant agreement in identifying malnutrition, with significantly higher identification rates in the high-risk (or positive) group ( p < 0.05). The AUCs were 0.978, 0.720, 0.868, 0.983, 0.957, and 0.716, respectively. In this BMI-based analysis, the GLIM criteria showed higher agreement with the malnutrition definition than the other five tools. The combination of the GLIM criteria with phase angle (PA) further improved discriminative ability. However, because BMI is an imperfect reference for malnutrition in Crohn’s disease, these findings should be considered exploratory. Independent validation using a comprehensive nutritional assessment is needed.