More economic 25 mg 13 C‐urea breath test can be effective in detecting primary Helicobacter pylori infection in children

Background and Aim:  The high cost of the 13 C‐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 2δ to 5δ 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 3.5δ. 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). Conclusion:  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.