title: More economic 25 mg 13C-urea breath test can be effective in detecting primary Helicobacter pylori infection in children.
abstract: OBJECTIVE
  The high cost of the 13C-urea breath test (UBT) limits its wide application for both epidemiological and clinical studies for diagnosing Helicobacter pylori infection. This study examined if a lower-dose UBT, applying 1 mg/kg of bodyweight (maximum 25 mg, UBT(25)), could introduce cost savings while preserving high diagnostic yields for primary H. pylori infection.
  
  
  METHODS
  Children aged less than 16 years were recruited after obtaining consent. Those children with administration of antibiotics or proton pump inhibitors within 1 month of the tests were excluded. Positive tests for both the UBT with 50 mg urea (UBT(50)) and the H. pylori stool antigen (HpSA) were qualifying criteria for H. pylori infection. Negative results for both indicated non-infection. The UBT(25) was conducted 1 week after the UBT(50). The cut-off points for the UBT(25) ranging from 2delta to 5delta were examined for their sensitivity, specificity and accuracy rates.
  
  
  RESULTS
  A total of 153 children were recruited (55% male; mean age 9.1 +/- 3.5 years). Both the UBT(50) and HpSA test were positive in 18 (13.1%) and negative in 119 children, respectively. The sensitivity and specificity of the UBT(25) were optimally achieved at 88.9% (95% confidence interval [CI]: 71.4-100) and 95.0% (95% CI: 91.1-99.9), judged with a cut-off point at 3.5delta. The diagnostic accuracy was significantly higher for children older than 7 years than for those younger than 7 years (98%vs 85%, P = 0.009).
  
  
  CONCLUSIONS
  Lower-dose UBT titration by bodyweight can cut costs while maintaining a highly reliable method to screen primary H. pylori infection in children older than 7 years, which is generally beyond school age.
authors.affiliation: Department of Pediatrics, Medical College, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Yao-Jong
authors.initials: YJ
authors.lastname: Yang
authors.forename: Bor-Shyang
authors.initials: BS
authors.lastname: Sheu
authors.forename: Shui-Cheng
authors.initials: SC
authors.lastname: Lee
authors.forename: Jiunn-Jong
authors.initials: JJ
authors.lastname: Wu
mesh_terms: D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D003365:Costs and Cost Analysis; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000191:economics; D016480:Helicobacter pylori; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014508:Urea / Q000008:administration & dosage*
chemical_list: D002247:Carbon Isotopes; D014508:Urea