Objective We sought to compare the quick sequential organ failure assessment (qSOFA) to systemic inflammatory response syndrome (SIRS), severe sepsis criteria and lactate levels for their ability to identify ED patients with sepsis with critical illness.

Methods We conducted this multicenter retrospective cohort study at five US hospitals, enrolling all adult patients admitted to these hospitals from their EDs with infectious disease-related illnesses from 1 January 2016 to 30 April 2016. We abstracted clinical variables for SIRS, severe sepsis and qSOFA scores, using values in the first 6 hours of ED stay. Our primary outcome was critical illness, defined as one or more of the composite outcomes of death, vasopressor use or intensive care unit (ICU) admission within 72 hours of presentation. We determined diagnostic test characteristics for qSOFA scores, SIRS, severe sepsis criteria and lactate level thresholds.

Main results Of 3743 enrolled patients, 512 (13.7%) had the primary composite outcome. The qSOFA scores were ≥1, >2 and 3 in 1839 (49.1%), 626 (16.7%) and 146 (3.9%) patients, respectively; 2202 (58.8%) met SIRS criteria and 1085 (29.0%) met severe sepsis criteria. qSOFA ≥1 and SIRS had similarly high sensitivity [86.1% (95% CI 82.8% to 89.0%) vs 86.7% (95% CI 83.5% to 89.5%)], but qSOFA ≥1 had higher specificity [56.7% (95% CI 55.0% to 58.5%) vs 45.6% (43.9% to 47.3%); mean difference 11.1% (95% CI 8.7% to 13.6%)]. qSOFA ≥2 had higher specificity than severe sepsis criteria [89.1% (88.0% to 90.2%) vs 77.5% (76.0% to 78.9%); mean difference 11.6% (9.8% to 13.4%)]. qSOFA ≥1 had greater sensitivity than a lactate level ≥2 (mean difference 24.6% (19.2% to 29.9%)).

Conclusion For patients admitted from the ED with infectious disease diagnoses, qSOFA criteria performed as well or better than SIRS criteria, severe sepsis criteria and lactate levels in predicting critical illness.