Risk Stratification and Mortality in Clostridioides difficile Infection: Clinical Determinants and Prognostic Assessment

Clostridioides difficile infection (CDI) remains a major cause of healthcare-associated morbidity and mortality, particularly among older adults and patients with recent healthcare exposure, underscoring the need for early risk stratification and accurate prognostic assessment. This retrospective observational study evaluated clinical, laboratory, and therapeutic factors associated with disease severity and in-hospital mortality, and assessed the predictive performance of the ATLAS score and the Charlson comorbidity index. A total of 101 adult inpatients with laboratory-confirmed CDI admitted to a Portuguese tertiary care hospital were included. Data were extracted from clinical records and analysed using comparative statistics, multivariable logistic regression, and Kaplan–Meier survival analysis. Advanced age, elevated white blood cell count, renal dysfunction, and prior exposure to multiple antibiotic classes were independently associated with increased disease severity and mortality. The ATLAS score demonstrated good discriminative ability, particularly for short-term mortality, and showed higher sensitivity compared with the Charlson comorbidity index. These findings provide additional evidence on clinical and laboratory factors associated with severe CDI and in-hospital mortality, while supporting the utility of the ATLAS score as a practical tool for early risk stratification in hospitalised patients.