Assessment of C-Reactive Protein Diagnostic Test Accuracy for Late-Onset Infection in Newborn Infants : A Systematic Review and Meta-analysis

Abstract

Is serum C-reactive protein level sufficiently accurate to aid the diagnosis of late-onset infection in newborn infants? In this systematic review and meta-analysis of 22 cohort studies (2255 infants) comparing the diagnostic test accuracy of serum C-reactive protein with microbiological culture, median specificity was 0.74 and pooled sensitivity was 0.62. Assuming a orwould miss 152 cases of infection and wrongly diagnose 156 cases. The findings suggest that serum C-reactive protein level is not sufficiently accurate to aid diagnosis or to inform treatment decisions in infants with suspected late-onset infection. Rapid and accurate diagnosis of late-onset infection in newborn infants could inform treatment decisions and avoid unnecessary administration of antibiotics. To compare the accuracy of serum C-reactive protein (CRP) with that of microbiological blood culture for diagnosing late-onset infection in newborns. MEDLINE (1946-2019), Embase (1946-2019), and Science Citation Index (1900-2019) databases were searched for references (any language). The MeSH search terms included were “exp infant, newborn/” or “premature birth/” plus free text synonyms; and “C-reactive protein/” plus free text synonyms; and “exp sepsis/” or “exp bacterial infections/” plus free text synonyms. The proceedings from relevant conferences and references of identified papers were scrutinized. Authors were contacted to request missing data. Cohort and cross-sectional studies were included that compared the accuracy of serum CRP levels with microbiological culture results to diagnose late-onset (>72 hours after birth) infection in newborns (any gestational age) hospitalized after birth. Two reviewers assessed study eligibility. Among 10 394 records, 148 studies were assessed as full texts. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline extension for Diagnostic Test Accuracy ( DTA ) reviews was followed. Two reviewers assessed the method quality of each study using guidance from the Cochrane Screening and Diagnostic Test Methods Group (adapted from the Quality Assessment of Diagnostic Accuracy Studies 2). The primary meta-analysis outcome was diagnostic test accuracy of serum CRP level taken at initial investigation of an infant with suspected late-onset infection. The median specificity (proportion of true-negative results) and calculated pooled sensitivity (proportion of true-positive results) were determined by generating hierarchical summary receiver characteristic operating curves. In total, 22 studies with 2255 infants were included (sample size range, 11-590 infants). Participants in most studies were preterm (<37 weeks) or very low-birth weight (<1500 g) infants. Two studies additionally enrolled infants born at term. Most studies (14 of 16) used a prespecified CRP level cutoff for a “positive” index test (5-10 mg/L) and the culture of a pathogenic microorganism from blood as the reference standard. Risk of bias was low with independent assessment of index and reference tests. At median specificity (0.74), pooled sensitivity was 0.62 (95% CI, 0.50-0.72). Adding serum CRP level to the assessment of an infant with a 40% pretest probability of late-onset infection (the median for the included studies) generated posttest probabilities of 26% for a negative test result and 61% for a positive test result. The findings suggest that determination of serum CRP level at initial evaluation of an infant with suspected late-onset infection is unlikely to aid early diagnosis or to select infants to undergo further investigation or treatment with antimicrobial therapy or other interventions. This systematic review and meta-analysis of cohort and cross-sectional studies compares the diagnostic test accuracies of serum C-reactive protein level vs microbiological culture for diagnosing late-onset infection among newborn infants.