title: The frequency of vesicoureteral reflux diagnosis is correlated with urbanization level of residence in pediatric population: a nationwide study in Taiwan.
abstract: OBJECTIVE
  To investigate the frequency and characteristics of newly diagnosed vesicoureteral reflux (VUR) in children younger than 18 years based on a nationwide database in Taiwan.
  
  
  METHODS
  The present study utilizes a subset of the Taiwan's National Health Insurance Research Database, known as the Longitudinal Health Insurance Database 2005, which contains the data of all paid medical benefit claims over 1997-2007 for a subset of 1,000,000 beneficiaries randomly drawn from the population of 22.72 million individuals during any part of the 2005 calendar year. Our analysis includes the data of all pediatric patients with the diagnosis of VUR.
  
  
  RESULTS
  A total of 738 subjects with VUR diagnosis were identified, including 412 (55.8%) boys and 326 (44.2%) girls. The peak age of VUR occurrence was the first year for males and 1-4 years for females. Approximately 49.7% of all subjects presented with urinary tract infection (UTI); moreover, there were significant differences between genders concerning the presence of UTI (RR = 0.8; p = 0.002). The occurrence rate of VUR in the pediatric population ranged from 2.63 in 1998 to 3.94 in 2003 per 10,000 children during 1998-2005. The frequency of newly-diagnosed VUR in the pediatric population was significantly correlated with urbanization levels of residence.
  
  
  CONCLUSIONS
  The nationwide, population-based study of pediatric VUR shows there were gender differences in age distribution and presence of UTI. Further studies are warranted to clarify the correlations between urbanization level of residence and occurrence of VUR.
authors.affiliation: Institute of Health and Welfare Policy, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wei-Yi
authors.initials: WY
authors.lastname: Huang
authors.forename: Yu-Fen
authors.initials: YF
authors.lastname: Chen
authors.forename: Hong-Chiang
authors.initials: HC
authors.lastname: Chang
authors.forename: Teng-Kai
authors.initials: TK
authors.lastname: Yang
authors.forename: Ju-Ton
authors.initials: JT
authors.lastname: Hsieh
authors.forename: Kuo-How
authors.initials: KH
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology; D014505:Urban Population / Q000706:statistics & numerical data; D014507:Urbanization; D014718:Vesico-Ureteral Reflux / Q000175:diagnosis / Q000453:epidemiology*; D055815:Young Adult
keywords: Age; Gender; Pediatric; Urbanization level; Vesicoureteral reflux