Abstract:

Objective To establish and evaluate a line chart model for the early diagnosis of neonatal septicemia by using peripheral blood-derived inflammation markers. Methods Totally，137 patients with neonatal septicemia and 114 non-infected newborns were enrolled，96 cases of neonatal septicemia patients were randomly selected as septicemia group，96 cases of non-infected newborns were selected as control group，and the remaining 59 newborns（41 cases of neonatal septicemia patients and 18 cases of non-infected newborns） were included in model verification group. The clinical data of all the newborns were collected，blood routine tests were performed，and the test items included white blood cell（WBC） count，hemoglobin（Hb），platelet（PLT） count，lymphocyte percentage（LYMPH%），neutrophil percentage（NEUT%），hematocrit（HCT），C-reactive protein（CRP），procalcitonin（PCT） and interleukin-6（IL-6）. Logistic regression analysis was used to evaluate the risk factors of neonatal septicemia，and a line chart model was constructed. Receiver operating characteristic（ROC） curve，decision curve and calibration curve were used to evaluate and validate the model. Kaplan-Meier survival curve was used to evaluate the probability of neonatal septicemia in different risk groups. Results There was statistical significance in WBC count，PLT count，Hb，NEUT%，CRP，PCT and IL-6 between septicemia group and control group（P<0.05），but there was no statistical significance in LYMPH% and HCT（P>0.05）. The results of Logistic regression analysis showed that the elevated levels of CRP，PCT and IL-6 were risk factors for neonatal septicemia [odds ratios（OR） were 2.943，2.862 and 2.915，respectively，P<0.05]. The total score of risk factors in the line chart was 239.78，and the corresponding incidence of neonatal septicemia was 71.86%. The C-index value of the line chart diagnosis model for neonatal septicemia was 0.934，the area under curve was 0.831，the sensitivity was 82.1%，and the specificity was 80.4%. The ideal curve in the calibration curve was close to the actual curve，the accuracy was good，the area under decision curve was 0.792，and the clinical net benefit rate of the model was high. According to the critical value of the line chart diagnosis model score，the occurrence probability of neonatal septicemia was classified into 3 groups，low risk（≤83.65），medium risk（>83.65-≤157.89） and high risk（>157.89） groups. The probability of neonatal septicemia was 29.47%，45.57% and 83.33%，respectively. Conclusions The line chart diagnosis model based on CRP，PCT and IL-6 is of value in early diagnosis of neonatal septicemia.

Key words: C-reactive protein, Procalcitonin, Interleukin-6, Neonatal septicemia, Line chart model