Aggregate Index of Systemic Inflammation and C-Reactive Protein/Albumin Ratio in Sepsis.

INTRODUCTION: This study aimed to evaluate the association between the Aggregate Index of Systemic Inflammation (AISI) and the C-reactive protein/albumin ratio (CAR) and the severity of sepsis and 28-d survival outcomes. METHODS: This retrospective cohort study enrolled 283 patients with sepsis, who were classified into sepsis and septic shock groups. The 28-d survival status of patients was recorded. Spearman's correlation analysis was performed. Receiver operating characteristic curves and Kaplan-Meier curves were plotted. Factors were selected using LASSO regression, and a logistic regression model was developed. RESULTS: Patients with septic shock exhibited higher AISI (904.23 ± 98.41 versus 789.89 ± 65.00) and CAR (3.23 ± 0.62 versus 2.29 ± 0.43) values than those with sepsis. AISI showed weak positive correlations with both Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment scores, whereas CAR demonstrated moderate positive correlations with these two scores. The combined AISI-CAR model achieved an area under the curve of 0.85 (95% confidence interval: 0.81∼0.89, P < 0.001), outperforming each individual index and APACHE II and Sequential Organ Failure Assessment scores used alone. AISI (OR = 2.79), CAR (OR = 2.00), and APACHE II (OR = 1.15) were independently associated with 28-d death. CONCLUSIONS: Patients with septic shock exhibit elevated AISI and CAR levels, both of which are associated with 28-d survival outcomes. Combined assessment of these two markers may aid in prognostic risk assessment and provide guidance for personalized clinical treatment. However, these conclusions require further validation through multicenter studies.