Use of Serum Procalcitonin in Evaluation of Febrile Infants: A Meta-analysis of 2317 Patients

BackgroundSerum procalcitonin (PCT) concentrations have been studied as a diagnostic test for serious bacterial infections (SBIs) in children. However, the utility of a single measurement in the evaluation of SBIs in febrile infants younger than 91 days is not clear.ObjectiveUse a systematic review and meta-analysis to determine: 1) the ability of serum PCT concentrations to identify febrile infants < 91 days of age at high and low risk for SBIs, and 2) to compare its utility with available clinical prediction rules.MethodsThe literature search identified studies of febrile infants segregated into risk groups using serum PCT concentrations. Some authors were contacted to provide subgroups < 91 days of age or to provide data with 0.3 ng/mL PCT cutoff values. Data were combined and validated using standard methodologies.ResultsSeven studies encompassing 2317 patients were identified; five of seven studies used a PCT discriminating concentration of 0.3 ng/mL. No heterogeneity or publication bias was identified. The overall relative risk (RR) was 3.97 (95% confidence interval [CI] 3.41–4.62) and was consistent by sensitivity analysis. The RR from a systematic review of clinical prediction rules was 30.6 (95% CI 7.0–68.13) and 8.75 (95% CI 2.29–15.2) for infants untreated and treated with antibiotics, respectively.ConclusionsAlone, measurement of serum PCT concentrations, though able to identify a group of young infants at risk for SBIs, is inferior to the available clinical prediction rules for identifying young, febrile infants at risk for SBIs. Serum concentrations ≤ 0.3 ng/mL may be helpful as an add-on test to current rules for identifying low-risk, febrile infants.