Systematic review and meta-analysis assessing the diagnostic test accuracy of procalcitonin in the diagnosis of invasive bacterial infections in febrile infants: a study protocol.

Introduction: Young febrile infants are at higher risk of invasive bacterial infections (IBIs) compared with older children. The clinical features of IBI are subtle in this cohort mandating that clinicians take a cautious approach to their initial assessment and management. This includes the measurement of blood biomarkers of infection such as C reactive protein (CRP) and procalcitonin (PCT). In the UK, PCT is not widely available and not recommended for routine use in hospital. This is in contrast to Europe and the USA where PCT is regularly used to assist clinical decision-making. The objective of this review and meta-analysis is to report the diagnostic test accuracy of PCT in detecting IBI in febrile infants less than 91 days old, compare its accuracy with CRP and define optimal PCT cut-off values in this cohort.

Methods And Analysis: A search strategy will include MEDLINE, EMBASE, Web of Science, The Cochrane Library and grey literature. There will be no language or date limitations. Diagnostic accuracy studies compliant with STARD criteria will be considered against eligibility criteria. Abstracts, then full texts, of potentially eligible studies will be independently screened for selection. Data extraction and quality assessment, using the QUADAS-2 tool, will be completed by two independent authors and a third author used for any inconsistencies. True positives, false positives, true negatives and false negatives will be pooled to collate specificity and sensitivity with 95% CIs. Results will be portrayed in forest plots, alongside their quality assessments.

Ethics And Dissemination: This review does not require ethical clearance. This review will be published in peer-reviewed journals and key messages will be disseminated through presentations at local and international conferences related to this field. The authors aim for this review to be completed and published in 2023.