Systemic immune-inflammation index in critically ill patients with renal failure: a retrospective cohort study from Medical Information Mart for Intensive Care IV (MIMIC-IV) database

• Published in: BMJ open Vol. 15; no. 6; p. e094203
• Main Authors: Su, Min-I, Hsiao, Chia-Ying, Chang, Yu-Cheng, Chang, Pi-Yi, Lee, Ying-Hsiang, Lin, Po-Lin, Chiou, Wei-Ru
• Format: Journal Article
• Language: English
• Published: England British Medical Journal Publishing Group 12.06.2025; BMJ Publishing Group LTD; BMJ Publishing Group
• Subjects: Adult intensive & critical care; Aged; Biomarkers - blood; Blood platelets; Blood pressure; Body mass index; Cohort analysis; Comorbidity; Creatinine; Critical Illness - mortality; Databases, Factual; Diabetes; End stage renal failure; Female; Heart attacks; Heart failure; Hemodialysis; Hemoglobin; Hospital Mortality; Hospitals; Humans; Immunity; Inflammation; Inflammation - immunology; Intensive care; Intensive Care Units; Kidney diseases; Kidney Failure, Chronic - immunology; Kidney Failure, Chronic - mortality; Lymphocytes; Male; Medical prognosis; Middle Aged; Missing data; Mortality; Neutrophils; Original Research; Patients; Physiology; Population; Proportional Hazards Models; Renal Medicine; Retrospective Studies; Rheumatic diseases; End stage renal failure; Retrospective Studies; Immunity; Adult intensive & critical care
• ISSN: 2044-6055; 2044-6055
• DOI: 10.1136/bmjopen-2024-094203

ObjectivesSystemic immune-inflammation index (SII) is a biomarker of inflammatory conditions; however, no scoring system has been evaluated for predicting mortality in patients with renal failure in intensive care unit (ICU). This study aimed to determine associations between SII level and mortality in patients with renal failure.DesignUsing the Medical Information Mart for Intensive Care IV (V.2.0) database (USA), this retrospective study included 837 patients who were admitted to ICU with end-stage renal disease (ESRD), between 2008 and 2019.Primary and secondary outcome measuresCox proportional-hazards models were used to evaluate correlations between SII and outcomes, expressing results as hazard ratios (HRs) with 95% confidence intervals (95% CIs). Regression analysis was used to determine associations between variables and SII.ResultsIn total, 837 adult patients from a total of 76 943 patients admitted to ICU were included, comprising 59.60% males with mean age 62.27±14.9 years and mean BMI 28.36±7.43 Kg/m2. Using median SII (1628 X 109 /L) as cut-off value, high (≥ 1628X109 /L) SII was also associated with an increased risk of ICU mortality (HR 1.97 (95% CI 1.15 to 3.35), p=0.034), in-hospital mortality (HR 1.95 (95% CI 1.23 to 3.09), p=0.017) and total mortality (HR 1.30 (95% CI 1.07 to 1.58), p=0.024).ConclusionsSII may predict mortality in critically ill patients admitted to ICU with ESRD. SII ≥ 1628×109 /L correlates significantly with increased ICU mortality, in-hospital mortality and total mortality.