A latent class approach for sepsis diagnosis supports use of procalcitonin in the emergency room for diagnosis of severe sepsis

Abstract

BackgroundGiven the acknowledged problems in sepsis diagnosis, we use a novel way with the application of the latent class analysis (LCA) to determine the operative characteristics of C-reactive protein (CRP), D-dimer (DD) and Procalcitonin (PCT) as diagnostic tests for sepsis in patients admitted to hospital care with a presumptive infection.MethodsCross-sectional study to determine the diagnostic accuracy of three biological markers against the gold standard of clinical definition of sepsis provided by an expert committee, and also against the likelihood of sepsis according to LCA. Patients were recruited in the emergency room within 24 hours of hospitalization and were follow-up daily until discharge.ResultsAmong 765 patients, the expert committee classified 505 patients (66%) with sepsis, 112 (15%) with infection but without sepsis and 148 (19%) without infection. The best cut-offs points for CRP, DD, and PCT were 7.8 mg/dl, 1616 ng/ml and 0.3 ng/ml, respectively; but, neither sensitivity nor specificity reach 70% for any biomarker. The LCA analysis with the same three tests identified a “cluster” of 187 patients with several characteristics suggesting a more severe condition as well as better microbiological confirmation. Assuming this subset of patients as the new prevalence of sepsis, the ROC curve analysis identified new cut-off points for the tests and suggesting a better discriminatory ability for PCT with a value of 2 ng/ml.ConclusionsUnder a “classical” definition of sepsis three typical biomarkers (CRP, PCT and DD) are not capable enough to differentiate septic from non-septic patients in the ER. However, a higher level of PCT discriminates a selected group of patients with severe sepsis.

Comparison between white blood cell count, procalcitonin and C reactive protein as diagnostic and prognostic biomarkers of infection or sepsis in patients presenting to emergency department

“…The diagnostic accuracy of the three biomarkers, according to latent class analysis (LCA) gold standard for diagnosis of sepsis, was demonstrated by high ROC curves (CRP 0.71; PCT 0.95; D-Dimer 0.73). They did not use a combination of the three biomarkers, but one was considered singularly [15]. Instead, the innovative and adjunctive information of our study is that a combination of the three studied biomarkers could improve diagnostic accuracy, even greater than a combination of only two of them.…”

“…However, these are also the most relevant risk factors for developing sepsis [1]. Moreover, in early stages of the process, the source of infection may be unclear and the related systemic response indistinguishable from non-infectious diseases [15].…”

Staging dementia based on caregiver reported patient symptoms: Implications from a latent class analysis

“…logistic regression with receiver operating characteristic (ROC) curve was conducted to identify the optimal cut-off values based on the assessment tools used. Similar analytical strategies have been used in other studies [40][41][42]. The Youden's J statistic (sensitivity + specificity -1) [43] was used in the cut-off selection.…”

Differences in the effectiveness of serum biomarkers for the diagnosis of bacterial infections in adult and elderly patients admitted to the emergency department

“…The facts that this marker can be measured in a very short time in serum and that it is an inexpensive test have increased its usability. Many studies have shown that PCT is a superior biomarker in separating infectious and noninfectious causes of disease in patients with signs of infection (11)(12)(13)(14).…”