Impact of patient adherence on the cost-effectiveness of noninvasive tests for the initial diagnosis of Helicobacter pylori infection in the United States

OBJECTIVE: Previous US-based economic models of noninvasive tests for diagnosis of Helicobacter pylori infection did not consider patient adherence or downstream costs of continuing infection. This analysis evaluated the long-term cost-effectiveness of the urea breath test (UBT), fecal antigen test (FAT), and serology for diagnosis of H. pylori infection after incorporating information regarding test adherence. MATERIALS AND METHODS: A decision-analytic model incorporating adherence information evaluated the cost-effectiveness of the UBT, FAT, and serology for diagnosis of H. pylori infection. Positive test results led to first-line triple therapy; no further action was taken for nonadherence or negative results. Excess lifetime costs and reduced quality-adjusted life-years (QALYs) were estimated for patients with continuing H. pylori infection. RESULTS: In the base-case scenario with estimated adherence rates of 86%, 48%, and 86% for the UBT, monoclonal FAT, and serology, respectively, corresponding expected total costs were US$424.99, $466.41, and $404.98/patient. Test costs were higher for the UBT, but were fully or partially offset by higher excess lifetime costs for the monoclonal FAT and serology. The QALYs gained/patient with the UBT vs monoclonal FAT and serology were 0.86 and 0.27, respectively. The UBT was dominant vs the monoclonal FAT, leading to lower costs and higher QALYs; the UBT was cost-effective vs serology (incremental cost/QALY gained $74). CONCLUSION: Based on a comprehensive modeled analysis that included consideration of patient test adherence and long-term consequences resulting from continuing H. pylori infection, the UBT provided the greatest economic value among noninvasive tests for diagnosis of H. pylori infection, because of high patient adherence and excellent test performance.