Usefulness of Urea Breath Test for Helicobacter Pylori Detection

PICHON RIVIERE, A.; AUGUSTOVSKI, F.; GARCIA MARTI, S.; GLUJOVSKY, D.; ALCARAZ, A.; LOPEZ, A.; BARDACH, A.; CIAPPONI, A; REY-ARES, L.; ROJAS, J; ELORRIAGA, N; REGUEIRO, A.; ROMANO, M

Documento de Evaluación de Tecnologías Sanitarias

IECS

Año: 2012 p. 1 - 30

1668-2793

Helicobacter pylori (H. pylori) is a bacterium which constitutes a risk factor for the development of gastric and/or duodenal ulcers, gastric cancer and MALT (Mucosa-Associated Lymphoid Tissue). Its prevalence is estimated to be 30-40% in the U.S., and is even greater in developing countries. In general, those patients with no other risk factors who present dyspepsia have indications to introduce changes in lifestyle as well as treatment with proton pump inhibitors. In those cases where the problem does not resolve, H. pylori assessment is indicated to define therapy.Several studies have demonstrated that bacterial eradication reduces the incidence of these diseases, causing gastric and duodenal ulcer remission at 12 months in 97% and 98%, respectively, when H. pylori infection is effectively treated, compared with 61% and 65% when the infection persists.According to the American College of Gastroenterology, the presence of H. pylori should be looked for whenever treatment is being considered for those positive cases. Which study is adequate depends on the need or not for performing and endoscopy and the characteristics and costs of the different diagnostic methods. The tests performed, when endoscopy is not required, include the evaluation of serum antibodies, urea breath test and antigen detection in stools.TechnologyThe urea breath test identifies H. pylori due to its urease activity. If the bacterium is present the radiolabeled urea intake of non-radioactive C13 or C14 isotopes results in the production of carbon dioxide, which can be quantified in the exhaled air.MethodsA bibliographic search was carried out on the main databases (MEDLINE, EMBASE, Cochrane, DARE, NHS EED), on Internet general search engines, in health technology assessment agencies and health systems. Priority was given to the inclusion of systematic reviews; controlled, randomized clinical trials (RCTs); health technology assessments and economic evaluations; clinical practice guidelines and coverage policies of other health systems.ResultsOne systematic review where non-invasive H. pylori diagnostic tests were evaluated and two cost-effective studies were found. In addition, clinical practice guidelines and health provider reports about this technology were found.One systematic review from 2009, evaluated 30 studies (range 22-316 patients each), half being adults and the other half children. The sensitivity observed was 75%-100% (compared with 50%-100% for antibodies and 50%-98% for antigens in stools) and specificity was 55%-100% (compared with 52%-100% for antibodies and 63%-100% for antigens in stools). When evaluating those studies which reported a sensitivity and a specificity >90%, 84% corresponded to the urea breath test and 62% to antigens in stools and less than 60% to antibodies.In 2007, a cost-effectiveness study was published whose model assumed a 25%-H. Pylori prevalence in patients with dyspepsia. It compared 3 arms: the urea breath test, the serology and the stool antigen test. The urea breath test yielded a correct diagnosis in 96.1% of the cases. However, the stool antigen test was less expensive and more effective (96.8% correct diagnosis).The clinical practice guidelines agree that non-invasive tests may be used together with medical treatment. In those cases where the problem does not resolve, H. pylori evaluation is usually indicated followed by further treatment. In many cases this diagnosis is used to replace endoscopy. Most cases suggest that there are no advantages on the use of one non-invasive over the other, in terms of diagnosis. In those cases where post-antibiotic treatment evaluation is indicated, the urea breath test or the stool antigen test is proposed.The American College of Gastroenterology mentions there is no test that should be considered the gold standard, but that clinical circumstances, pre-test infection likelihood, availability and costs are to be considered. The American College considers the urea breath test as a test with excellent predictive positive and negative value, regardless of infection prevalence, with over a 95% sensitivity and specificity and good reproducibility. Although C13 radiation is low, the use of C14 is proposed for children and pregnant women.The different health systems consider the urea breath test as a medically necessary technology for patients with recent dyspepsia onset, under 55 years old, with persistent symptoms after a 2-week-course antibiotic treatment, for recurrent dyspepsia and to assess the success of H. pylori eradication.The estimated cost for the urea breath test is $200-$300 (Argentine pesos, March/2011). The stool antigen test as well as the serology test cost is $100, whereas the endoscopy is about $800-$1000.ConclusionsAt present, there are different diagnostic tests to identify the presence of H. pylori. The urea breath test presents an adequate sensitivity and specificity profile. There is consensus among most clinical practice guidelines found about the use of non-invasive tests for low-risk patients with dyspepsia and without alarming signs. They also agree that the urea breath test, the stool antigen test and serology test might be an equivalent initial diagnostic tool, although the serology test should not be used for post-treatment control.The recommendation to use one test and not the other may be made only after performing an economic evaluation considering the different therapy schemes and their costs.