Combining procalcitonin with the qSOFA and sepsis mortality prediction

To investigate whether procalcitonin (PCT) can improve the performance of quick sequential organ failure assessment (SOFA) score in predicting sepsis mortality, we conducted a retrospective multicenter cohort study with independent validation in a prospectively collected cohort in 3 tertiary medical centers. Patients with presumed sepsis were included. Serum PCT levels were measured at admission. Quick SOFA score and systemic inflammatory response syndrome (SIRS) criteria were calculated for each patient. PCT levels were assigned into 0, 1, and 2 points for a serum level of <0.25, 0.25 to 2, and >2 ng/mL, and added to the quick sepsis-related organ failure assessment (qSOFA) score. The incremental value of PCT to qSOFA was then evaluated by logistic regression, receiver-operating characteristic (ROC) curve, and reclassification analysis. In all, 1318 patients with presumed severe infection were enrolled with a 30-day mortality of 13.5%. Serum level of PCT showed a high correlation with qSOFA score and 30-day inhospital mortality. The area under the ROC curve was 0.56 for SIRS criteria, 0.67 for qSOFA score, and 0.73 for qSOFA_PCT in predicting 30-day mortality. The risk prediction improvement was reflected by a net reclassification improvement of 35% (17%–52%). Incorporation of PCT into the qSOFA model could raise the sensitivity to 86.5% (95% confidence interval 80.6%–91.2%). In the validation cohort, qSOFA_PCT greatly improved the sensitivity to 90.9%. A simple modification of qSOFA score by adding the ordinal scale of PCT value to qSOFA could greatly improve the suboptimal sensitivity problem of qSOFA and may serve as a quick screening tool for early identification of sepsis.