Prediction of high-grade vesicoureteral reflux after pediatric urinary tract infection: external validation study of procalcitonin-based decision rule.

Abstract

BACKGROUND:

Predicting vesico-ureteral reflux (VUR) ≥3 at the time of the first urinary tract infection (UTI) would make it possible to restrict cystography to high-risk children. We previously derived the following clinical decision rule for that purpose: cystography should be performed in cases with ureteral dilation and a serum procalcitonin level ≥0.17 ng/mL, or without ureteral dilatation when the serum procalcitonin level ≥0.63 ng/mL. The rule yielded a 86% sensitivity with a 46% specificity. We aimed to test its reproducibility.

STUDY DESIGN:

A secondary analysis of prospective series of children with a first UTI. The rule was applied, and predictive ability was calculated.

RESULTS:

The study included 413 patients (157 boys, VUR ≥3 in 11%) from eight centers in five countries. The rule offered a 46% specificity (95% CI, 41-52), not different from the one in the derivation study. However, the sensitivity significantly decreased to 64% (95%CI, 50-76), leading to a difference of 20% (95%CI, 17-36). In all, 16 (34%) patients among the 47 with VUR ≥3 were misdiagnosed by the rule. This lack of reproducibility might result primarily from a difference between derivation and validation populations regarding inflammatory parameters (CRP, PCT); the validation set samples may have been collected earlier than for the derivation one.

CONCLUSIONS:

The rule built to predict VUR ≥3 had a stable specificity (ie. 46%), but a decreased sensitivity (ie. 64%) because of the time variability of PCT measurement. Some refinement may be warranted.

• Authors: Sandrine Leroy, François Bouissou, Anna Fernandez-Lopez, Metin K Gurgoze, Kyriaki Karavanaki, Tim Ulinski, Silvia Bressan, Geogios Vaos, Pierre Leblond, Yvon Coulais, Carlos Luaces Cubells, A Denizmen Aygun, Constantinos J Stefanidis, Albert Bensman, Liviana Da Dalt, Liviana DaDalt, Stefanos Gardikis, Sandra Bigot, Dominique Gendrel, Gérard Bréart, Martin Chalumeau
• Journal: PloS one (PLoS One) Vol. 6 Issue 12 Pg. e29556 ( 2011) ISSN: 1932-6203 [Electronic] United States
• PMID: 22216314 (Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)
• Copyright: © 2011 Leroy et al.

Chemical References

• CALCA protein, human
• Protein Precursors
• Calcitonin
• Calcitonin Gene-Related Peptide

Topics

• Calcitonin (blood)
• Calcitonin Gene-Related Peptide
• Child
• Decision Making
• Female
• Humans
• Male
• Prospective Studies
• Protein Precursors (blood)
• Sensitivity and Specificity
• Urinary Tract Infections (blood, complications)
• Vesico-Ureteral Reflux (blood, complications, diagnosis)