Hospitalizations for pediatric stone disease in United States, 2002-2007.

PURPOSE: Although more common in adults, urolithiasis recently has been occurring with increasing frequency in children. Single institution reviews from 1950 to 1990 revealed that urolithiasis accounts for 1 in 7,600 to 1 in 1,000 pediatric hospitalizations. Stone prevalence and risk factors for hospitalization are less defined in children in North America compared to adults. To identify pediatric hospital admissions due to a diagnosis of urinary stones, we examined Pediatric Health Information System data from 41 freestanding pediatric hospitals.

MATERIALS AND METHODS: We retrospectively studied patients younger than 18 years hospitalized between 2002 and 2007. The Pediatric Health Information System database, a validated collection of pediatric hospital data, was searched for inpatients with a primary ICD-9 diagnosis of urolithiasis.

RESULTS: Among more than 2.7 million pediatric inpatients from 2002 to 2007, 3,989 hospitalizations were for 3,815 patients with urolithiasis. In contrast to adults, girls had a 1.5-fold greater likelihood of being hospitalized for stones. More than half of the children (53.1%) were younger than 13 years (mean 12.3, SD 4.23). Most patients (88%) were white. Stone hospitalizations were more common in the North Central region compared to the South. Hospitalizations for stones increased slightly in August and September. Nephrectomy was performed in nearly 1% of stone hospitalizations (29 of 3,170).

CONCLUSIONS: Children with stones now account for 1 in 685 pediatric hospitalizations in the United States. Surprisingly more than half of the patients are younger than 13 years at hospitalization. Similar to findings in adults, white race and occurrence in late summer months increase the risk of stone hospitalization. However, male gender and geographic location in the Southeast are not risk factors, demonstrating the unique aspects of pediatric stone hospitalization.