Prognostic Value of CRP-to-Albumin Ratio in Elderly ICU Patients: A Retrospective Study

Background: Systemic inflammation and malnutrition are key contributors to adverse outcomes among older adults admitted to the ICU. The prognostic relevance of CRP-to-albumin ratio (CAR), reflecting combined inflammatory and nutritional status, was evaluated in relation to 28-day mortality.Methods: A retrospective cohort of 207 older adults (≥65 years) admitted to the ICU between December 2024 and June 2025 was analyzed. Demographic variables, clinical features, and laboratory parameters were extracted from electronic health records. All-cause mortality at 28 days served as the primary outcome, while prognostic assessment was performed using ROC analysis alongside multivariable logistic regression models.Results: A 28-day all-cause mortality of 26.1% was observed. Non-survivors exhibited significantly higher CAR, CRP, APACHE II, and SOFA scores (p 0.001). In multivariable models, CAR remained independently associated with mortality (OR 1.14, 95% CI 1.01–1.28, p = 0.034). An AUC of 0.77 (95% CI 0.70–0.84) was observed for CAR, indicating good discriminatory ability.Conclusions: The CAR independently associated with short-term mortality in geriatric ICU patients and may serve as a simple, inexpensive biomarker for early risk stratification and outcome prediction.