Objective:In critical care medicine, extubation is a pivotal step in the management of mechanically ventilated patients. Accurately determining the optimal timing for extubation is essential for minimizing complications and improving patient survival rates. However, reliable indicators to predict clinical outcomes following extubation remain scarce. This study aims to identify a novel and robust predictor of extubation success in critically ill patients, thereby providing clinicians with more precise decision-making support.Methods:This retrospective study analyzed data from adult patients who underwent mechanical ventilation and were evaluated for extubation across six intensive care units (ICUs) at Xiangya Third Hospital of Central South University between January 2019 and December 2021. Patients with a history of difficult airway, upper airway obstruction, or neuromuscular disorders affecting respiratory function were excluded. The primary outcome was the reintubation rate within 24 hours post-extubation. Categorical variables were analyzed using the chi-square test or Fisher’s exact test, while between-group differences were assessed with the Mann-Whitney U test. Significant predictors identified in univariate analysis were further evaluated via multivariate logistic regression. The diagnostic accuracy of the maximum inspiratory pressure/body mass index (MIP/BMI) ratio was determined using receiver operating characteristic (ROC) curve analysis, with the Youden index employed to establish the optimal cutoff value. Kaplan-Meier analysis and log-rank tests were used to compare extubation success rates between groups. Statistical analyses were performed using SPSS V28.0 and Stata v.16.0. Results:Diabetes comorbidity ( OR: 8.181, 95% CI: 1.659–40.338) and MIP/BMI ( OR: 0.140, 95% CI: 0.042–0.469) were identified as independent predictors of reintubation. The area under the ROC curve (AUROC) for MIP/BMI was 0.753, demonstrating good predictive accuracy. The optimal cutoff value for MIP/BMI was 1.26 cmH 2O/(kg·m 2), with a sensitivity of 55.3% and specificity of 92.3%. Kaplan-Meier analysis revealed a significantly higher reintubation rate in the low MIP/BMI group compared to the high MIP/BMI group ( P = 0.009), further validating its predictive utility. Conclusions:This study establishes MIP/BMI as a novel and clinically valuable predictor of extubation outcomes in critically ill patients. A cutoff value of 1.26 cmH 2O/(kg·m 2) was found to best predict successful extubation.