Proposal of simplified sepsis-induced coagulopathy criteria (SIC-2) for the detection of early-phase disseminated intravascular coagulation in sepsis.

BACKGROUND

Sepsis-induced coagulopathy (SIC) was introduced to identify early coagulation abnormalities in sepsis and to predict progression to overt disseminated intravascular coagulation (DIC). However, inclusion of the Sequential Organ Failure Assessment (SOFA) may conflate coagulation-specific biology with overall illness severity.

OBJECTIVES

This study aimed to evaluate whether removal of the SOFA component preserves the diagnostic and prognostic performance of SIC and to determine whether a simplified coagulation-centered construct (SIC-2) maintains clinical utility.

METHODS

In a retrospective cohort of 18 086 patients with sepsis from the Medical Information Mart for Intensive Care IV database, we compared the original SIC with SIC-2 using a noninferiority framework. Predictive performance for overt DIC within 5 intensive care unit days, 28-day mortality, and organ support-free outcomes was evaluated for both discrimination and calibration using the area under the receiver operating characteristic curve (AUC) and calibration slopes.

RESULTS

Both definitions showed comparable and excellent discrimination for overt DIC (AUC 0.850 vs 0.854; P = .37). For 28-day mortality, SIC demonstrated modest but slightly higher discrimination than SIC-2 (AUC 0.621 vs 0.614; P < .001), although the absolute difference (ΔAUC = 0.007) was small. Associations with intensive care unit-free and ventilator-free days were significant for both scores, with marginally stronger separation for SIC. Under a noninferiority interpretation, the removal of SOFA preserved the prediction of the overt DIC trajectory.

CONCLUSION

The predictive contribution of SOFA within SIC primarily reflects downstream organ dysfunction severity rather than coagulation-specific biology. The simplified, coagulation-centered SIC-2 maintains overt DIC prediction while improving conceptual clarity. These findings support considering SIC-2 as a screening phenotype for early sepsis-associated coagulopathy rather than a composite severity index.