Analyzing how the components of the SOFA score change over time in their contribution to mortality

Objective: Determine how each organ component of the SOFA score differs in its contribution to mortality risk and how that contribution may change over time. Methods: We performed multivariate logistic regression analysis to assess the contribution of each organ component to mortality risk on Days 1 and 7 of an intensive care unit stay. We used data from two publicly available datasets, eICU Collaborative Research Database (eICU-CRD) (208 hospitals) and Medical Information Mart for Intensive Care IV (MIMIC-IV) (1 hospital). The odds ratio of each SOFA component that contributed to mortality was calculated. Mortality was defined as death either in the intensive care unit or within 72 hours of discharge from the intensive care unit. Results: A total of 7,871 intensive care unit stays from eICU-CRD and 4,926 intensive care unit stays from MIMIC-IV were included. Liver dysfunction was most predictive of mortality on Day 1 in both cohorts (OR 1.3; 95%CI 1.2-1.4; OR 1.3; 95%CI 1.2-1.4, respectively). In the eICU-CRD cohort, central nervous system dysfunction was most predictive of mortality on Day 7 (OR 1.4; 95%CI 1.4-1.5). In the MIMIC-IV cohort, respiratory dysfunction (OR 1.4; 95%CI 1.3-1.5) and cardiovascular dysfunction (OR 1.4; 95%CI 1.3-1.5) were most predictive of mortality on Day 7. Conclusion: The SOFA score may be an oversimplification of how dysfunction of different organ systems contributes to mortality over time. Further research at a more granular timescale is needed to explore how the SOFA score can evolve and be ameliorated.