The research team, led by Alino Demean Loghin and Brandon Noyon, co-primary authors, together with Jocelyn Gravel and Caroline Quach of the CHU Sainte-Justine research centre, set out to measure the appropriateness of empiric antibiotic prescriptions. Empiric therapy is the treatment started before laboratory results identify the exact bacterium and its antibiotic susceptibilities, so it must be selected based on clinical presentation, local resistance patterns, and institutional guidelines. When clinicians reach for the wrong drug or the wrong dose at this stage, children may receive unnecessary broad-spectrum exposure, and the selective pressure that drives antimicrobial resistance intensifies.

Antimicrobial resistance, often abbreviated AMR, is recognized by the World Health Organization as one of the most serious threats to global public health. Every inappropriate prescription contributes to the problem by killing susceptible bacteria while leaving resistant strains to flourish. Pediatric emergency departments represent a particularly important setting for stewardship efforts because they handle enormous volumes of common infections, and urinary tract infections in children are a frequent trigger for antibiotic prescribing. The Montreal team viewed this as an ideal opportunity to audit real-world practice against a data-driven local guideline.

The study design was straightforward but rigorous. The investigators reviewed charts of children aged 18 years or younger who presented to the emergency department between January and December 2022 with a presumptive diagnosis of urinary tract infection and who had a urine sample collected for urinalysis and culture. Children with concurrent infections were excluded to keep the analysis focused. From a total of 1,029 children diagnosed with a urinary tract infection during the study year, the team randomly sampled 449 charts for detailed evaluation, of which 358, or 79.8 percent, proved eligible for the final analysis.

The cohort reflected the typical epidemiology of pediatric urinary infections. The median age was 34 months, meaning half the children were younger than roughly three years old, and 253 of the 358 participants, or 70.7 percent, were female, consistent with the shorter female urethra facilitating bacterial ascent into the bladder. About a quarter of the children, 96 cases or 26.8 percent, were diagnosed with cystitis, an infection confined to the bladder, while the remainder had pyelonephritis, the more serious upper urinary tract infection involving the kidneys. This distinction matters clinically because the two conditions call for different antibiotic strategies and different durations of therapy.

The primary outcome was defined as the appropriateness of the empiric prescription, judged by whether both the antibiotic choice and the dose matched the hospital’s local guidelines. The researchers also collected a rich set of independent variables, including age, sex, past medical history such as urinary tract abnormalities, prior infections, and vesicoureteral reflux, documented allergies, presenting temperature, the method used to collect the urine sample, urinalysis results, and the bacteria ultimately identified on culture. Inter-rater reliability was assessed on a five percent sample of chart reviews to ensure the evaluations were consistent, a methodological safeguard that strengthens confidence in the reported proportions.

The headline result was that 75 of the 358 prescriptions, or 20.9 percent, were deemed inappropriate, with a 95 percent confidence interval of 16.9 to 25.5 percent. In other words, roughly one in five children received an empiric antibiotic regimen that did not conform to the hospital’s own recommendations. But the aggregate figure concealed a dramatic asymmetry between infection types. For cystitis, 61.5 percent of prescriptions were inappropriate, with a confidence interval spanning 51.0 to 71.2 percent, whereas for pyelonephritis the inappropriate rate was only 6.1 percent, with a confidence interval of 3.5 to 9.7 percent.

Delving into the reasons behind these failures, the researchers found that the choice of antibiotic itself was the culprit in 61 of the 75 inappropriate cases, accounting for 83 percent of the deviations. Dosing errors made up the remainder. This pattern suggests that the problem is not careless arithmetic but a systematic mismatch between what prescribers reach for and what the local guideline recommends for lower urinary tract infections. For cystitis, oral agents such as trimethoprim-sulfamethoxazole are typically favored when local susceptibility profiles permit, and the high inappropriateness rate hints that clinicians may be defaulting to broader or otherwise non-recommended agents for bladder infections.

Why would guideline adherence be so much worse for cystitis than for pyelonephritis? The authors point to an opportunity for improved antibiotic stewardship rather than offering a definitive explanation, but several plausible mechanisms fit the data. Bladder infections are perceived as mild and self-limited, which may lower the perceived stakes of antibiotic selection and encourage habitual prescribing. Pyelonephritis, by contrast, carries visible stakes, with febrile children at risk of renal scarring and sepsis, prompting closer attention to guidelines. Emergency department workflow, familiarity with specific drugs, and ambiguity about which children have upper versus lower disease at the moment of prescribing may all contribute to the gap.

The implications extend well beyond a single Montreal hospital. The study demonstrates that even within an institution equipped with local guidelines and susceptibility data, adherence can vary enormously by diagnosis, and that targeted interventions should focus where the failures cluster. Stewardship programs that combine electronic decision support, prescriber feedback, and regular audits of empiric prescribing could plausibly close much of the cystitis gap, reducing unnecessary broad-spectrum exposure in thousands of children each year. As resistance profiles of common uropathogens such as Escherichia coli continue to evolve, the study serves as a reminder that the routine prescriptions, not just the dramatic cases, determine the long-term effectiveness of the antibiotic arsenal.

Subject of Research: Guideline adherence of antibiotic prescriptions for pediatric urinary tract infections in an emergency department

Article Title: Guideline adherence of antibiotic prescriptions for urinary tract infections in a pediatric emergency department: a retrospective cohort study

Article References: Demean Loghin, A., Noyon, B., Gravel, J., & Quach, C. (2026). Guideline adherence of antibiotic prescriptions for urinary tract infections in a pediatric emergency department: a retrospective cohort study. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07757-8

Image Credits: AI Generated

DOI: 10.1186/s12887-026-07757-8

Keywords: urinary tract infection, antibiotics, pediatrics, emergency department, antimicrobial resistance, antibiotic stewardship, cystitis, pyelonephritis, clinical guidelines, retrospective cohort study, prescription appropriateness, Escherichia coli