OBJECTIVES: To determine performance of C-reactive protein (CRP) in the diagnosis of early-onset sepsis, and to assess patient outcomes with and without routine use of CRP.

STUDY DESIGN: This was a retrospective cohort study of infants admitted to 2 neonatal intensive care units. CRP was used routinely in early-onset sepsis evaluations during 2009-2014; this period was used to determine CRP performance at a cut-off of ≥10 mg/L in diagnosis of culture-confirmed early-onset sepsis. Routine CRP use was discontinued during 2018-2020; outcomes among infants admitted during this period were compared with those in 2012-2014.

RESULTS: From 2009 to 2014, 10 134 infants were admitted; 9103 (89.8%) had CRP and 7549 (74.5%) had blood culture obtained within 3 days of birth. CRP obtained ±4 hours from blood culture had a sensitivity of 41.7%, specificity 89.9%, and positive likelihood ratio 4.12 in diagnosis of early-onset sepsis. When obtained 24-72 hours after blood culture, sensitivity of CRP increased (89.5%), but specificity (55.7%) and positive likelihood ratio (2.02) decreased. Comparing the periods with (n = 4977) and without (n = 5135) routine use of CRP, we observed lower rates of early-onset sepsis evaluation (74.5% vs 50.5%), antibiotic initiation (65.0% vs 50.8%), and antibiotic prolongation in the absence of early-onset sepsis (17.3% vs 7.2%) in the later period. Rate and timing of early-onset sepsis detection, transfer to a greater level of care, and in-hospital mortality were not different between periods.

CONCLUSIONS: CRP diagnostic performance was not sufficient to guide decision-making in early-onset sepsis. Discontinuation of routine CRP use was not associated with differences in patient outcomes despite lower rates of antibiotic administration.

OBJECTIVES: To determine performance of C-reactive protein (CRP) in diagnosis of early-onset sepsis (EOS), and to assess patient outcomes with and without routine use of CRP.

STUDY DESIGN: Retrospective cohort study of infants admitted to two neonatal intensive care units. CRP was routinely used in EOS evaluations during 2009-2014; this period was utilized to determine CRP performance at a cut-off of ≥10 mg/L in diagnosis of culture-confirmed EOS. Routine CRP use was discontinued during 2018-2020; outcomes among infants admitted during this period were compared with those in 2012-2014.

RESULTS: From 2009-2014, 10,134 infants were admitted; 9,103 (89.8%) had CRP and 7,549 (74.5%) had blood culture obtained within 3 days of birth. CRP obtained ±4 hours from blood culture had a sensitivity of 41.7%, specificity 89.9% and positive likelihood ratio 4.12 in diagnosis of EOS. When obtained 24-72 hours after blood culture, sensitivity of CRP increased (89.5%), but specificity (55.7%) and positive likelihood ratio (2.02) decreased. Comparing the periods with (n=4,977) and without (n=5,135) routine use of CRP, we observed lower rates of EOS evaluation (74.5% vs. 50.5%), antibiotic initiation (65.0% vs. 50.8%), and antibiotic prolongation in the absence of EOS (17.3% vs. 7.2%) in the later period. Rate and timing of EOS detection, transfer to a higher level of care, and in-hospital mortality were not different between periods.

CONCLUSIONS: CRP diagnostic performance was not sufficient to guide decision-making in EOS. Discontinuation of routine CRP use was not associated with differences in patient outcomes despite lower rates of antibiotic administration.