Top-Down versus Bottom-Up Approach in Children Presenting with Urinary Tract Infection: Comparative Effectiveness...

Area of Science:

• Pediatric Nephrology
• Diagnostic Imaging
• Infectious Diseases

Background:

• Initial imaging strategies for pediatric urinary tract infections (UTIs) remain a subject of debate.
• Current approaches include renal/bladder ultrasound with voiding cystourethrogram (VCUG) (bottom-up) or dimercaptosuccinic acid (DMSA) scan (top-down).
• Comparative effectiveness data between these diagnostic pathways are limited.

Purpose of the Study:

• To conduct a comparative effectiveness analysis of the top-down versus bottom-up imaging approaches for pediatric UTIs.
• To evaluate the impact of each approach on recurrent UTIs, utilization of VCUG, and exposure to continuous antibiotic prophylaxis (CAP).

Main Methods:

• A simulation using 1,000 hypothetical sets of 500 children based on RIVUR/CUTIE trial data.
• Top-down approach: Initial DMSA scan, followed by VCUG only if renal scarring is present.
• Bottom-up approach: Initial VCUG, with assumed continuous antibiotic prophylaxis (CAP) for all children with vesicoureteral reflux (VUR).

Main Results:

• The top-down approach was associated with a statistically significant increase in recurrent UTIs compared to the bottom-up approach (24.4% vs 18.0%, p=0.045).
• The bottom-up approach led to significantly more VCUGs (100% vs 2.4%, p <0.001).
• The top-down approach substantially reduced CAP exposure (0.4% vs 25% of patients, and 162 vs 5 days/person, p <0.001).

Conclusions:

• The top-down imaging approach for pediatric UTIs is linked to a slightly higher rate of recurrent infections.
• However, the top-down strategy significantly decreases the necessity for VCUG and reduces exposure to continuous antibiotic prophylaxis (CAP).
• These findings provide valuable insights for optimizing diagnostic pathways in pediatric UTI management.