Appropriate Timing of the 14C-Urea Breath Test to Establish Eradication of Helicobacter pylori Infection.

OBJECTIVE: The aim of this study was to determine the performance characteristics of the ¹⁴C-urea breath test (UBT) performed 2 wk after the completion of therapy for Helicobacter pylori using a 4 to 6 wk study as the gold standard. METHODS: Patients with active Helicobacter pylori infection at four medical centers received proton pump inhibitor-based triple or quadruple therapy for 10-14 days. Patients underwent the ¹⁴C-UBT 2 and 4 -6 wk after the completion of therapy. A positive test was defined as ¹⁴CO₂ excretion of >200 dpm, a negative test as <50 dpm, and an equivocal test as >50 but <200 dpm. Performance characteristics of the 2-wk UBT were calculated using the 4 to 6-wk result as a gold standard. RESULTS: Eighty-five patients were enrolled and 82 patients (mean ± SD age, 62 ± 15 yr; 15 women) completed the protocol. Four patients had equivocal UBT results and were excluded from the analysis. Of the 78 patients, 68 (87%) had a negative 4 to 6-wk UBT. The 2-week UBT yielded a sensitivity of 90% (95% confidence interval 72-100%), specificity of 99% (97-100%), and accuracy of 97% (93-100%). In patients with a persistently positive UBT, ¹⁴CO₂ excretion at 2 wk was significantly lower than at 4-6 wk after therapy (p = 0.03). CONCLUSIONS: A UBT performed 2 wk after therapy yielded results comparable to 4 to 6 wk testing. Further studies to evaluate the optimal time of confirmatory testing in the age of more effective proton pump inhibitor-based triple therapies are warranted. [ABSTRACT FROM AUTHOR]