title: Comparison of Accuracy Between13C- and14C-Urea Breath Testing: Is an Indeterminate-Results Category Still Needed?
abstract: Helicobacter pyloriinfection is the leading cause of peptic ulcer disease. The purpose of this study was, first, to assess the difference in the distribution of negative versus positive results between the older14C-urea breath test and the newer13C-urea breath test and, second, to determine whether use of an indeterminate-results category is still meaningful and what type of results should trigger repeated testing.Methods:A retrospective survey was performed of all consecutive patients referred to our service for urea breath testing. We analyzed 562 patients who had undergone testing with14C-urea and 454 patients who had undergone testing with13C-urea.Results:In comparison with the wide distribution of negative14C results, negative13C results were distributed farther from the cutoff and were grouped more tightly around the mean negative value. Distribution analysis of the negative results for13C testing, compared with those for14C testing, revealed a statistically significant difference between the two. Within the13C group, only 1 patient could have been classified as having indeterminate results using the same indeterminate zone as was used for the14C group. This is significantly less frequent than what was found for the14C group.Discussion:Borderline-negative results do occur with13C-urea breath testing, although less frequently than with14C-urea breath testing, and we will be carefully monitoring differences falling between 3.0 and 3.5 %Δ.13C-urea breath testing is safe and simple for the patient and, in most cases, provides clearer positive or negative results for the clinician.
authors.affiliation: Nuclear Medicine Service, Hôpital du Sacré-Coeur de Montréal, Montreal, Canada mathieu.charest@gmail.com.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Charest
authors.affiliation: Nuclear Medicine Service, Hôpital du Sacré-Coeur de Montréal, Montreal, Canada.
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Bélair
mesh_terms: D001944:Breath Tests / Q000379:methods*; D002247:Carbon Isotopes / Q000737:chemistry*; D002250:Carbon Radioisotopes / Q000737:chemistry*; D016481:Helicobacter Infections / Q000175:diagnosis; D006801:Humans; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014508:Urea / Q000032:analysis* / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D002250:Carbon Radioisotopes; C000615234:Carbon-14; D014508:Urea; C000615229:Carbon-13
keywords: 13C; 14C; accuracy; breath test; distribution; helicobacter pylori