Timing of voiding cystourethrography after febrile urinary tract infection in children: a systematic review

Correspondence to Dr Marcus Weitz, Nephrology, University Children"s Hospital Zurich, Zurich 8032, Switzerland; [email protected]

What is already known on this topic?

• Some studies suggest that an early voiding cystourethrography following febrile urinary tract infection does not affect the detection of vesicoureteric reflux.

• Despite these results, insufficient statistical power and methodological quality have limited reliable conclusions for clinical practice.

What this study adds?

• This systematic review and meta-analysis provides a robust data set showing that early timing of voiding cystourethrography does not influence the detection of vesicoureteric reflux in children.

Introduction

With an estimated prevalence of 25%–40% in children following febrile urinary tract infection (fUTI), vesicoureteric reflux (VUR) is the most common anomaly of the kidney and urinary tract.^{1 2} Voiding cystourethrography (VCUG) is considered the method of choice to diagnose VUR.³ In the past, VCUG was often deferred for 3–6 weeks after fUTI due to the beliefs of transient inflammatory changes at the level of vesicoureteric junction, and therefore a higher risk of false-positive or false-negative detection rates of VUR.^4–9 There is a growing body of evidence that timing of VCUG seems to be an independent factor for detection of VUR; however, small sample sizes, unclear comparability of the results and lack of assessment of the quality of the studies preclude robust conclusions.^{6 10 11} For these reasons, there are currently no recommendations for optimal timing of VCUG after fUTI, diagnostic management remains controversial and clinical practice varies widely.^{6 12–19} The objective of this intervention review was to assess whether an early VCUG (<8 days after onset of antibiotic therapy) compared with a delayed VCUG (≥8 days after onset of antibiotic therapy) affects the prevalence of VUR for any graduation and for each grade. The timing for early VCUG was selected from the clinical, not evidence-based practice according to which at least 7 days of antibiotic therapy following fUTI is regarded as the minimum time period for effective treatment.²⁰ For the purpose of our systematic review, an intervention review was used instead of a diagnostic test accuracy review because the patient population of interest was diagnosed with the same diagnostic tool (VCUG) comparing two intervention groups without a test comparator.

Methods

This systematic review was conducted in accordance with...