OBJECTIVE: This study analyses the 13C-urea breath test with the aim of determining the optimal time interval between dosing and breath sampling and examines the feasibility of having patients perform the test without supervision at home. DESIGN: Prospective study comparing the 13C-urea breath test with four antral biopsy-based tests in a random population undergoing upper gastrointestinal endoscopy. SETTING: One university hospital and one general hospital. PATIENTS: One hundred and four patients were included; 61 were Helicobacter pylori-positive and 43 H. pylori-negative according to biopsy-based tests. INTERVENTIONS: The 13C-urea breath test was performed at home by collecting a baseline and two post-dosing samples; the next day it was performed clinically by collecting a baseline and six post-dosing samples. A 100 mg dose of 13C-urea and a test meal were used. OUTCOME MEASURES: The breath samples collected were analysed. Excess delta 13CO2/12CO2 values above five per million were considered positive. RESULTS: The specificity of the clinical test was 100% whereas that of the home-based test was 95.1%. The sensitivity of the clinical test depended on the time interval between dosing and collection of the evaluated sample. Sensitivity was 100% if the sample was taken 50 min or more after dosing. The home-based test had a sensitivity of 94.8%. CONCLUSION: To obtain maximum sensitivity (100%) using the single-sample technique the sample has to be collected at least 50 min after dosing. It is feasible to have the test performed at home. Patient selection and thorough instruction are necessary.
OBJECTIVE: This study analyses the 13C-urea breath test with the aim of determining the optimal time interval between dosing and breath sampling and examines the feasibility of having patients perform the test without supervision at home. DESIGN: Prospective study comparing the 13C-urea breath test with four antral biopsy-based tests in a random population undergoing upper gastrointestinal endoscopy. SETTING: One university hospital and one general hospital. PATIENTS: One hundred and four patients were included; 61 were Helicobacter pylori-positive and 43 H. pylori-negative according to biopsy-based tests. INTERVENTIONS: The 13C-urea breath test was performed at home by collecting a baseline and two post-dosing samples; the next day it was performed clinically by collecting a baseline and six post-dosing samples. A 100 mg dose of 13C-urea and a test meal were used. OUTCOME MEASURES: The breath samples collected were analysed. Excess delta 13CO2/12CO2 values above five per million were considered positive. RESULTS: The specificity of the clinical test was 100% whereas that of the home-based test was 95.1%. The sensitivity of the clinical test depended on the time interval between dosing and collection of the evaluated sample. Sensitivity was 100% if the sample was taken 50 min or more after dosing. The home-based test had a sensitivity of 94.8%. CONCLUSION: To obtain maximum sensitivity (100%) using the single-sample technique the sample has to be collected at least 50 min after dosing. It is feasible to have the test performed at home. Patient selection and thorough instruction are necessary.