Validation of quick sequential organ failure assessment score for poor outcome prediction among emergency department patients with suspected infection

Objective The quick sequential organ failure assessment (qSOFA) score, which includes mentation, systolic blood pressure, and respiratory rate, was developed to identify serious sepsis in out-of-hospital or emergency department (ED) settings. We evaluated the ability of the qSOFA score to predict poor outcome in South Korean ED patients with suspected infection. Methods The qSOFA score was calculated for adult ED patients with suspected infection. Patients who received intravenous or oral antibiotics in the ED were considered to have infection. In-hospital mortality rate, admission rate, intensive care unit (ICU) admission rate, length of hospital stay (LOS), and lactate levels were compared between the qSOFA score groups. Receiver operating characteristic curves and area under the receiver operating characteristic curve values for in-hospital mortality were calculated according to qSOFA cut-off points and lactate levels. Results Of 2,698 patients, in-hospital mortality occurred in 134 (5.0%). The mortality rate increased with increasing qSOFA score (2.2%, 6.4%, 17.5%, and 42.4% for qSOFA scores 0, 1, 2, and 3, respectively, P<0.001). The admission rate, ICU admission rate, LOS, and lactate level also increased with increasing qSOFA score (all P<0.001). The area under the receiver operating characteristic curve values for predicting in-hospital mortality associated with qSOFA score, lactate >= 2 mmol/L, and lactate >= 4 mmol/L were 0.719 (95% confidence interval [CI], 0.670 to 0.768), 0.657 (95% CI, 0.603 to 0.710), and 0.632 (95% CI, 0.571 to 0.693), respectively. Conclusion Patients with a higher qSOFA score had higher admission, ICU admission, and in-hospital mortality rates, longer LOS, and higher lactate level. The qSOFA score showed better performance for predicting poor outcome than lactate level.