The early change of SOFA score as a prognostic marker of 28-day sepsis mortality: analysis through a derivation and a validation cohort

BACKGROUND: Since the Sepsis-3 criteria, change in Sequential Organ Failure Assessment (SOFA) score has become a key component of sepsis identification. Thus, it could be argued that reversal of this change (Δ(SOFA)) may reflect sepsis response and could be used as measure of efficacy in interventional trials. We aimed to assess the predictive performance of Δ(SOFA) for 28-day mortality. METHODS: Data from two previously published randomized controlled trials were studied: the first reporting on patients with severe Gram-negative infections as a derivation cohort and the second reporting on patients with ventilator-associated pneumonia as a validation cohort. Only patients with sepsis according to the Sepsis-3 definition were included in this analysis. SOFA scores were calculated on days 1, 2, 3, 5, 7, 14, and 28. RESULTS: We included 448 patients within the derivation cohort and 199 within the validation cohort. Mean SOFA scores on day 1 were 6.06 ± 4.07 and 7.84 ± 3.39, and 28 day mortality 22.8% and 29.6%, respectively. In the derivation cohort, the earliest time point where Δ(SOFA) score predicted mortality was day 7 (AUROC (95% CI) 0.84 (0.80–0.89); p < 0.001). The best tradeoff for prediction was found with 25% changes (78% sensitivity, 80% specificity); less than 25% decrease of admission SOFA was associated with increased mortality (odds ratio for death 14.87). This finding was confirmed in the validation cohort. CONCLUSIONS: Δ(SOFA) on day 7 is a useful early prognostic marker of 28-day mortality and could serve as an endpoint in future sepsis trials alongside mortality. TRIAL REGISTRATION: ClinicalTrials.gov numbers NCT01223690 and NCT00297674