title: Ethnic factors in the variability of primary vesico-ureteral reflux with age.
abstract: OBJECTIVE
  To determine any ethnic difference in the rate of spontaneous decrease in the incidence of primary vesico-ureteral reflux (VUR).
  
  
  METHODS
  Voiding cystourethrograms on 738 patients with urinary tract infection were reviewed, and the incidence of primary vesico-urethral reflux was correlated with age, gender and ethnic origin.
  
  
  RESULTS
  There was a gradual decrease in the incidence of primary VUR in whites between 0-10 years, while the incidence of primary VUR in blacks was very low and remained the same. After 10 years of age, no difference was present.
  
  
  CONCLUSIONS
  The possibility of delayed maturation of the antireflux mechanism in whites is considered as a possible explanation, and the possibility of an ethnic basis for this is suggested.
authors.affiliation: Department of Radiology, University of South Alabama, 2451 Fillingim Street, 301 Mastin Building, Mobile, AL 36617, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Melhem
authors.forename: M D
authors.initials: MD
authors.lastname: Harpen
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D044383:Black People; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D014718:Vesico-Ureteral Reflux / Q000175:diagnosis / Q000208:ethnology*; D044465:White People