title: Epidemiological trends in pediatric urolithiasis at United States freestanding pediatric hospitals.
abstract: OBJECTIVE
  Anecdotal and lay press reports suggest that the incidence of pediatric urolithiasis is increasing but reliable data are lacking. The objective of this study was to examine trends in the epidemiology of urolithiasis at pediatric hospitals nationwide.
  
  
  METHODS
  The Pediatric Health Information System database is a national database covering 42 freestanding United States pediatric hospitals that captures inpatient admissions, and emergency department and outpatient surgery visits. We searched the Pediatric Health Information System database to identify children (18 years old or younger) treated for urolithiasis between 1999 and 2008. Patients with urolithiasis were measured as a proportion of the total number of patients seen per hospital annually. Trends were verified by comparing results to 2 other common pediatric diagnoses-appendicitis and viral bronchiolitis.
  
  
  RESULTS
  We identified 7,921 children diagnosed with urolithiasis during the study period. The total number of children with urolithiasis seen in Pediatric Health Information System hospitals increased from 125 in 1999 to 1,389 in 2008. Mean number of stone cases per hospital per year increased from 13.9 to 32.6. Compared to total hospital patients, the proportion of patients with pediatric urolithiasis increased from 18.4 per 100,000 in 1999 to 57.0 per 100,000 in 2008, an adjusted annual increase of 10.6% (p <0.0001). Urolithiasis also increased compared to appendicitis (p <0.0001) and bronchiolitis (p <0.0001).
  
  
  CONCLUSIONS
  Even after correcting for increases in total patient volume at Pediatric Health Information System hospitals, there has been a significant increase in the number of children diagnosed with and treated for urolithiasis at these hospitals in the last decade.
authors.affiliation: Department of Urology, Children's Hospital Boston, Boston, Massachusetts 02115, USA. jon.routh@gmail.com
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Routh
authors.forename: Dionne A
authors.initials: DA
authors.lastname: Graham
authors.forename: Caleb P
authors.initials: CP
authors.lastname: Nelson
mesh_terms: D000293:Adolescent; D000554:Ambulatory Care Facilities; D002648:Child; D002675:Child, Preschool; D005260:Female; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D008297:Male; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D052878:Urolithiasis / Q000453:epidemiology*