Abstract
Background: Frailty is a key determinant of outcomes in critically ill elderly patients, but data from Portugal remain limited. To our knowledge, this is the first study to examine the prevalence and prognostic impact of frailty among elderly ICU patients in a Portuguese hospital setting. Objective: To determine the prevalence of frailty among elderly patients admitted to an intensive care unit (ICU) in southern Portugal and to examine its crude associations with illness severity, organ support, and mortality outcomes. Methods: We conducted a retrospective cohort study including 125 patients aged ≥ 65 years admitted to the polyvalent ICU of Hospital de Faro over the last six months of 2024. Data included demographics, comorbidities, Charlson Comorbidity Index (CCI), severity scores (SOFA, SAPS II, APACHE II), and frailty status assessed by the Clinical Frailty Scale (CFS). Outcomes were the need for organ support, ICU and hospital mortality, and length of stay. Results: Frailty (CFS ≥ 5) was identified in 30.4% of patients. Frail patients were older, had higher comorbidity burden (CCI), and presented with significantly higher severity scores at admission. They also required more invasive support, including vasopressors and invasive mechanical ventilation, while acute kidney injury (AKI) requiring renal replacement therapy (RRT) was similar between groups. ICU mortality was significantly higher among frail patients (50.0% vs. 31.0%), as was hospital mortality (76.3% vs. 33.3%). Length of ICU stay did not differ, although frail patients tended to have longer hospitalizations overall. Conclusions: Frailty was highly prevalent and strongly associated with increased severity, greater need for organ support, and higher mortality. Routine frailty assessment at ICU admission may enhance prognostic accuracy and support patient-centered decision-making.