Abstract

Evaluating how the SOFA score components vary in their contribution to mortality over time

Yanran Li¹, Yanran Li¹, Barbara Lam², Ziyue Chen³, Yugang Jia⁴, Leo Anthony Celi⁴, Heather Mattie¹, Jesse Raffa⁴ (1)Department of Biostatistics, Harvard T.H. Chan School of Public Health, (2)Department of medicine, Beth Israel Deaconess Medical Center, (3)Genome institute of singapore, A¹STAR, Singapore, Singapore, (4)Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA

APHA 2022 Annual Meeting and Expo

Background: The Sequential Organ Failure Assessment (SOFA) score is an important predictor of in-hospital mortality. It may also be an oversimplification of the evolution of sepsis because it presents the six organ components–respiratory, hematologic, renal, hepatic, neurologic, and cardiovascular–as equal contributors to mortality over time.

Methods: We conducted a retrospective cohort study of patients using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database, a publicly available database with patients admitted to a tertiary academic medical center in Boston, MA, USA. We included all patients who had first-time ICU stays and were alive with available SOFA component scores at Day-1 and Day-7 respectively. Organ dysfunction was defined as a corresponding SOFA component score of more than 0 at any time in the last 24 hours. Our primary composite outcome, mortality, was defined as ICU death, hospital death within 72 hours of ICU discharge, or discharge to hospice within 72 hours of ICU discharge. Two logistic regression models were built to evaluate the strength of association between organ dysfunction and mortality for each cohort. In both models, we adjusted for age, gender, ethnicity and mechanical ventilation status.

Results: Of the 52096 and 7047 patients alive at Day-1 and Day-7 respectively, 4657 (8.94%) and 1377 (19.54%) had the composite outcome by Day-7. Admission renal dysfunction was documented in 2897 (53.0%) of African American patients, and around 35%-38% non-African American patients. The magnitude of the associations between specific organ system dysfunction varied considerably when comparing the effect of organ dysfunction collected at Day-1 or Day-7. Cardiovascular and coagulation dysfunction saw their association with the outcome rise significantly comparing their specific organ dysfunctions at Day-1 and Day-7. Liver and renal dysfunction at Day-7 while still strongly associated with mortality was significantly attenuated when compared to Day-1 (Liver: Day-1 OR=2.35 [2.17-2.55]; Day-7 OR=1.72 [1.45-2.04]; Renal: Day-1 OR=2.05 [1.91-2.19]; Day-7 OR=1.51 [1.46-1.74]).

Conclusion: The individual organ components of the SOFA score are not equal contributors to mortality over time. We observe higher rates of renal disease in African American patients. The importance of the renal component of SOFA is of increased importance during early admission. It might improve outcomes in this population if early ICU admission was targeted in African Americans with kidney disease, along with a focus of addressing renal dysfunction during the first hours of ICU admission.