Clinical prediction rules for childhood urinary tract infections: a cross-sectional study in ambulatory care

Abstract

BackgroundDiagnosing childhood urinary tract infections (UTIs) is challenging. Clinical prediction rules may help to identify children that require urine sampling. However, there is a lack of research to determine the accuracy of the scores in general practice.AimTo validate clinical prediction rules (UTI Calculator [UTICalc], A Diagnosis of Urinary Tract Infection in Young Children [DUTY], and Gorelick score) for paediatric UTIs in primary care.Design & settingPost-hoc analysis of a cross-sectional study in 39 general practices and two emergency departments (EDs). The study took place in Belgium from March 2019–March 2020.MethodPhysicians recruited acutely ill children aged ≤18 years and sampled urine systematically for culture. Per rule, an apparent validation was performed, and sensitivities and specificities were calculated with 95% confidence intervals (CIs) per threshold in the target group. For the DUTY coefficient-based algorithm, a logistic calibration was performed and the area under the receiver operating characteristic curve (AUC) was calculated with 95% CI.ResultsOf 834 children aged ≤18 years recruited, there were 297 children aged <5 years. The UTICalc and Gorelick score had high-to-moderate sensitivity and low specificity: UTICalc (≥2%) 75% and 16%, respectively; Gorelick (≥2 variables) 91% and 8%, respectively. In contrast, the DUTY score ≥5 points had low sensitivity (8%) but high specificity (99%). Urine samples would be obtained in 72% versus 38% (UTICalc), 92% versus 38% (Gorelick) or 1% versus 32% (DUTY) of children, compared with routine care. The number of missed infections per score was 1/4 (UTICalc), 2/23 (Gorelick), and 24/26 (DUTY). The UTICalc + dipstick model had high sensitivity and specificity (100% and 91%), resulting in no missed cases and 59% (95% CI = 49% to 68%) of antibiotics prescribed inappropriately.ConclusionIn this study, the UTICalc and Gorelick score were useful for ruling out UTI, but resulted in high urine sampling rates. The DUTY score had low sensitivity, meaning that 92% of UTIs would be missed.