Clinical Determinants of 90-Day Mortality After Tracheostomy in Critically Ill Patients: A Multicenter Retrospective Cohort Study

Background and Objectives: Tracheostomy is frequently performed in critically ill patients requiring prolonged invasive mechanical ventilation; however, factors associated with intermediate-term mortality after tracheostomy remain poorly characterized. This study aimed to identify clinical and procedural factors associated with 90-day all-cause mortality after tracheostomy in ICU patients. Materials and Methods: This retrospective multicenter cohort study included 292 adult patients who underwent tracheostomy in two tertiary ICUs between 1 October 2023 and 1 June 2025. Demographic characteristics, admission diagnoses, comorbidities, clinical severity scores, procedural variables, microbiological culture results, and survival data were collected. Univariate analyses, multivariable binary logistic regression, Cox proportional hazards regression, receiver operating characteristic (ROC) analysis, and Kaplan–Meier survival analysis were performed. Results: The overall 90-day all-cause mortality rate was 74.7%. Age, Charlson Comorbidity Index, and APACHE II score were significantly associated with 90-day mortality in univariate analyses, whereas tracheostomy timing and technique were not. In multivariable logistic regression analysis, the Charlson Comorbidity Index and APACHE II score were independently associated with mortality. Cox proportional hazards regression confirmed that both APACHE II score and Charlson Comorbidity Index were independently associated with mortality over time. ROC analysis demonstrated moderate discriminative performance for age, Charlson Comorbidity Index, and APACHE II score. Conclusions: In critically ill patients undergoing tracheostomy, 90-day mortality was high and was driven primarily by acute illness severity and comorbidity burden rather than procedural characteristics. These findings support incorporating biological vulnerability, expected recovery potential, and goals-of-care discussions into tracheostomy decision-making.