# Evaluation of the Prognostic Ability of the Antithrombin/Creatinine Ratio in Critically Ill Patients: Comparison With Sequential Organ Failure Assessment (SOFA) Score and Novel Antithrombin-modified SOFA Score

## TL;DR

This study found that the antithrombin/creatinine ratio is a useful tool for predicting mortality in ICU patients, similar to the SOFA score.

## Contribution

The study introduces the antithrombin/creatinine ratio as a novel, easily calculable prognostic marker for critically ill patients.

## Key findings

- The AT/Cre ratio had a prognostic accuracy (AUC: 0.71) comparable to the SOFA score (AUC: 0.75).
- A lower AT/Cre ratio was significantly associated with increased mortality risk.
- AT/Cre values differed significantly between patient clusters with varying prognoses.

## Abstract

Purpose: The objective of the study was to evaluate the prognostic ability of the antithrombin/creatinine (AT/Cre) ratio in critically ill patients and compare it with the Sequential Organ Failure Assessment Score (SOFA) score.

Methods: This retrospective cohort study was conducted at two hospitals and included patients admitted to the ICUs between January 2018 and December 2019 who had their AT activity measured within 24 hours of ICU admission. The primary endpoint was mortality at discharge. Statistical analyses included receiver operating characteristic (ROC) curve analysis, K-means clustering, and the Cox proportional hazards model.

Results: The study included 267 patients, of whom 173 (64.8%) were male. The median age was 69 years. The AT/Cre ratio demonstrated prognostic accuracy of mortality at discharge (AUC: 0.71, cut-off: 53.6) comparable to the SOFA score (AUC: 0.75, cut-off: 8.0). A lower AT/Cre ratio was significantly associated with increased mortality risk in multivariate analyses (hazard ratio (HR): 0.98, 95%CI: 0.98-0.99). When patients were categorized into four clusters, AT/Cre values differed significantly between clusters (p <0.0001), with higher values in clusters with a favorable prognosis.

Conclusion: The AT/Cre ratio showed prognostic performance comparable to SOFA, although its incremental value beyond established scores was not evaluated in this study. It is simple to calculate and may be valuable for early risk stratification and treatment decisions.