Sex prevalence of pediatric kidney stone disease in the United States: an epidemiologic investigation.

Objectives: To define the sex prevalence of inpatient hospital discharges for pediatric patients diagnosed with upper urinary tract stone disease.
Methods: The study examined inpatient admissions for pediatric urolithiasis in 2003, using the Healthcare Cost and Utilization Project Kids' Inpatient Database. We used the International Classification of Disease, 9th edition, Clinical Modification codes, to identify patients with a principal diagnosis of renal (592.0) or ureteral (592.1) calculi. Sex prevalence was assessed, and the results were stratified by age group.
Results: In the 2003 Kids' Inpatient Database, the sex distribution among pediatric patients with stone formation varied significantly by age. In the first decade of age, a male predominance was found that had shifted to a female predominance in the second decade. Overall, however, girls in the pediatric population were more commonly affected by stones than were boys.
Conclusions: In this nationally representative sample, the sex distribution of pediatric urolithiasis varied with age, with boys more commonly affected in the first decade of age and girls in the second decade. Although the reason for this unique epidemiologic finding is not readily apparent, additional studies can build on this hypothesis-generating work.