Objective To investigate relationship between neutrophil to lymphocyte ratio(NLR)and late-onset sepsis(LOS)in premature infants.Methods A total of 57 premature infants with LOS admitted to Maternal and Child Medical Center of Anhui Medical University neonatal department from January 2018 to April 2024 and 110 non-septicemic premature infants selected for the same period were retrospectively analyzed.Logistic regression model was used to analyze the association between NLR and LOS.Restricted cubic splines(RCS)were used to analyze the nonlinear association between NLR and LOS,and to analyze the difference between the inflammatory indicators of continuous monitoring.Results According to Logistic regression model,NLR was found to be an independent risk factor for LOS in premature infants.Based on RCS,we found that when NLR＜1.02,there was no significant correlation with LOS risk,and when NLR≥ 1.02,the risk with LOS increased exponentially.In terms of continuous monitoring,NLR is more valuable than C-reactive protein and procalcitonin in evaluating the effect of treatment.Conclusion NLR is an independent risk factor for LOS in premature infants.When NLR≥1.02,the risk of LOS in premature infants increases exponentially.Continuous monitoring of NLR is of high value in evaluating the treatment effect.

Objective To investigate relationship between neutrophil to lymphocyte ratio(NLR)and late-onset sepsis(LOS)in premature infants.Methods A total of 57 premature infants with LOS admitted to Maternal and Child Medical Center of Anhui Medical University neonatal department from January 2018 to April 2024 and 110 non-septicemic premature infants selected for the same period were retrospectively analyzed.Logistic regression model was used to analyze the association between NLR and LOS.Restricted cubic splines(RCS)were used to analyze the nonlinear association between NLR and LOS,and to analyze the difference between the inflammatory indicators of continuous monitoring.Results According to Logistic regression model,NLR was found to be an independent risk factor for LOS in premature infants.Based on RCS,we found that when NLR＜1.02,there was no significant correlation with LOS risk,and when NLR≥ 1.02,the risk with LOS increased exponentially.In terms of continuous monitoring,NLR is more valuable than C-reactive protein and procalcitonin in evaluating the effect of treatment.Conclusion NLR is an independent risk factor for LOS in premature infants.When NLR≥1.02,the risk of LOS in premature infants increases exponentially.Continuous monitoring of NLR is of high value in evaluating the treatment effect.