Evaluation of the C-reactive protein-albumin-lymphocyte (CALLY) index as a prognostic marker in patients with sepsis.

backgroundSepsis remains a leading cause of mortality worldwide, and early identification of high-risk patients is essential. The C-reactive protein–albumin–lymphocyte (CALLY) index has emerged as a potential prognostic biomarker but has not been widely studied in emergency department (ED) populations.

methodsWe conducted a retrospective cohort study including adult patients diagnosed with sepsis upon ED admission. The CALLY index was calculated as (albumin × lymphocyte count) / C-reactive protein (CRP), using laboratory values obtained at presentation. The primary outcome was 30-day all-cause mortality. Predictive performance was assessed using multivariable logistic regression with least absolute shrinkage and selection operator (LASSO) variable selection, calibration metrics, and Receiver Operating Characteristic (ROC) curve analyses.

resultsA total of 669 patients were included, with a 30-day mortality rate of 23% (n = 156). Non-survivors had significantly higher CRP (107.30 ± 40.97 vs. 94.01 ± 28.09 mg/L, p = 0.002), lower albumin (2.81 ± 0.30 vs. 3.59 ± 0.22 g/dL, p < 0.001), and lower lymphocyte count (0.71 ± 0.31 vs. 1.30 ± 0.40 × 10⁹/L, p < 0.001). The mean CALLY index was markedly elevated in deceased patients (69.7 ± 54.2 vs. 23.1 ± 15.6, p < 0.001). The area under the ROC of the CALLY index was 0.906 (95% CI, 0.879–0.934). At the threshold yielding the maximum Youden Index (31.32), the sensitivity was 0.853, specificity was 0.854, and accuracy was 0.852.

conclusionThe CALLY index is a simple and accessible biomarker independently associated with 30-day mortality in ED patients with sepsis and may support early risk stratification in acute care. CLINICAL TRIAL NUMBER: Not applicable.