Prehospital assessment and diagnostic accuracy of the qSOFA score in patients transported to the emergency department by emergency medical services (EMS)

Objective: This study aimed to evaluate the association between the prehospital quick Sequential Organ Failure Assessment (qSOFA) score and the diagnosis of sepsis, as well as the diagnostic accuracy of the qSOFA score in predicting sepsis among patients transported to the emergency department by Emergency Medical Services (EMS). In addition, the relationship between the qSOFA score and the patients' clinical course and early prognostic indicators was investigated. Materials and Methods: This retrospective, observational, single-center cohort study was conducted in the Emergency Department of Bolu Abant İzzet Baysal University İzzet Baysal Training and Research Hospital between January 1, 2022, and December 31, 2024. A total of 1,077 adult patients transported to the emergency department by EMS, whose prehospital vital signs were completely recorded, were included in the study. The diagnosis of sepsis was determined according to the Sepsis-3 criteria based on the SOFA score. The association between the prehospital qSOFA score and the diagnosis of sepsis was evaluated. In addition, the diagnostic accuracy of qSOFA was analyzed using sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratios, and receiver operating characteristic (ROC) analysis. A p-value of <0.05 was considered statistically significant. Results: Of the 1,077 patients included in the study, 896 (83.19%) were diagnosed with sepsis, whereas 181 (16.81%) had a non-septic clinical condition. For predicting sepsis, a prehospital qSOFA score of ≥2 demonstrated a sensitivity of 34.38%, specificity of 90.61%, positive predictive value of 94.77%, and negative predictive value of 21.81%. The positive likelihood ratio (LR+) was 3.66, and the negative likelihood ratio (LR−) was 0.72. In the logistic regression analysis, a qSOFA score of ≥2 was significantly associated with sepsis, with an odds ratio (OR) of 5.05 (95% confidence interval [CI]: 3.01–8.48). In the ROC analysis, the area under the curve (AUC) was 0.625 for the prehospital qSOFA score, 0.658 for lactate, and 0.714 for the combined model including qSOFA and lactate. The combined model demonstrated greater discriminative performance than qSOFA alone. Conclusion: The prehospital qSOFA score demonstrated high specificity but low sensitivity in identifying patients at high risk of sepsis. Nevertheless, a qSOFA score of ≥2 was significantly associated with sepsis and proved to be a valuable indicator for identifying patients at risk of an unfavorable early clinical course. The discriminative performance improved when qSOFA was combined with lactate, suggesting that evaluating qSOFA together with supportive biomarkers during prehospital triage may enhance clinical utility.