Validity and reliability of GLIM malnutrition criteria in cardiac surgery.

Introduction: Malnutrition is common in cardiac surgery patients and it´s associated with adverse clinical outcomes. However, there are no validated criteria for the nutritional diagnosis in this population. Objective: To determine the criterion validity and inter-rater reliability of the GLIM criteria for the diagnosis of malnutrition and the prediction of outcomes in cardiac surgery. Materials and Methods: Validation study in adults scheduled for cardiac surgery. Concurrent validity was established with the Subjective Global Assessment and the predictive validity with 30-day hospital readmission. Reliability was assessed with two professionals. The analyses and cut-off points of the GLIM validation guide were followed. Statistical processing was performed in R and Jamovi. Results: Inter-rater reliability of GLIM was demonstrated, with almost perfect agreement (Kappa 0.94, 95% CI 0.88-0.99, p<0.001), as well as its predictive validity for hospital readmission (RRa 2.59, 95% CI 1.09 - 7.02, p 0.04). Thresholds for concurrent validity were not met (sensitivity 88.0%, CI 95% 68.8-97.5%; specificity 76.9%, CI 95% 56.4-91.0%). Discussion: The lack of concurrent validity may be explained by differences in muscle mass estimation between diagnostic methods. The results are consistent with previous literature supporting the reliability and predictive ability of GLIM. Conclusion: GLIM criteria are reliable and predict relevant outcomes in cardiac surgery, supporting their usefulness for nutritional diagnosis and their potential application in the early identification of patients eligible for preoperative optimization interventions.