Use of serum procalcitonin in evaluation of febrile infants: a meta-analysis of 2317 patients

Background: Serum 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.

Objective: Use 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.

Methods: The 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.

Results: Seven 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.

Conclusions: Alone, 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.