Accuracy of qSOFA for the diagnosis of sepsis-3: a secondary analysis of a population-based cohort study.

BACKGROUND: We aimed to evaluate the accuracy of quick Sequential (sepsis-related) Organ Failure Assessment (qSOFA) for the diagnosis of sepsis-3, and to analyze the prognosis of infected patients in wards over-diagnosed with qSOFA but missed by sepsis-3, and those missed by qSOFA but in accordance with sepsis-3 criteria. We also intended to validate the performance of qSOFA as one predictor of outcome in patients with suspicion of infection. METHODS: We reviewed the medical records of 1,716 adult patients with infection who were hospitalized from July 1st, 2012 to June 30th, 2014 in the Yuetan subdistrict of Beijing, China. Based on the sepsis-3 criteria and qSOFA score proposed by the Third International Consensus Definitions for Sepsis and Septic Shock, these patients were categorized into four groups: qSOFA(-)sepsis(-), qSOFA(+)sepsis(-), qSOFA(-)sepsis(+), and qSOFA(+)sepsis(+). Multivariate logistic regression analysis was used to determine the independent risk factors for in-hospital mortality. The area under the receiver operating characteristic curves (AUROCs) of the qSOFA(+) group were compared with the sepsis(+) group for in-hospital mortality, ICU admission, and invasive ventilation. RESULTS: Among the 1,716 patients with infection, there were 935 patients (54.5%) with sepsis, and 640 patients (37.3%) with qSOFA ≥2. There were 610 patients in the qSOFA(-)sepsis(-) group, 171 in the qSOFA(+)sepsis(-) group, 466 in the qSOFA(-)sepsis(+) group, and 469 in the qSOFA(+)sepsis(+) group. In the logistic regression analysis, increasing age, bedridden status, and malignancy were all independent risk factors of hospital mortality. Sepsis and qSOFA ≥2 were also independent risk factors of hospital mortality, with an adjusted OR of 3.85 (95% CI: 2.70-5.50) and 13.92 (95% CI: 9.87-16.93) respectively. qSOFA had a sensitivity of 50.2% and a specificity of 78.1% for sepsis-3. The false-positive [qSOFA(+)sepsis(-)] group had 38 patients (22.2%) die during hospitalization, and an adjusted OR of 9.20 (95% CI: 4.86-17.38). In addition, the false-negative [qSOFA(-)sepsis(+)] group had a hospital mortality rate of 7.3% (34/466) and an adjusted OR of 2.59 (95% CI: 1.39-4.83). In comparison, patients meeting neither qSOFA nor sepsis criteria had the lowest hospital mortality [2.6% (16/610)], whereas patients with both qSOFA ≥2 and sepsis had the highest hospital mortality [56.5% (265/469)], with an adjusted OR of 42.02 (95% CI: 24.31-72.64). The discrimination of in-hospital mortality using qSOFA (AUROC, 0.846; 95% CI, 0.824-0.868) was greater compared with sepsis-3 criteria (AUROC, 0.834; 95% CI, 0.805-0.863; P<0.001). CONCLUSIONS: In our analysis, the sensitivity(Se) of qSOFA for the diagnosis of sepsis was lower, and qSOFA score ≥2 might identify a group of patients at a higher risk of mortality, regardless of being septic or not.