Final answer:
The most cost-effective initial diagnostic measure for the CFO concerned about Helicobacter pylori infection is the urea breath test, due to its accuracy and non-invasive nature.
Step-by-step explanation:
Many people experience indigestion or dyspepsia, which may present with upper abdominal fullness, heartburn, nausea, and belching. While it can often be alleviated with lifestyle changes such as eating more slowly or avoiding certain foods and medications, it can also be indicative of conditions like GERD or peptic ulcers. When symptoms persist, as in the case of the CFO with abdominal discomfort and concern about Helicobacter pylori infection, the most cost-effective initial diagnostic measure is a non-invasive test. In this scenario, the urea breath test, a simple and reliable test for detecting the presence of H. pylori, would be favored over an immediate endoscopy, empirical treatment, a rapid antibody test, or a fecal antigen test due to its balance of accuracy, cost, and convenience.