OBJECTIVES-Guidelines emphasize that irritable bowel syndrome (IBS) is not a diagnosis of exclusion and encourage clinicians to make a positive diagnosis using the Rome criteria alone. Yet many clinicians are concerned about overlooking alternative diagnoses. We measured beliefs about whether IBS is a diagnosis of exclusion, and measured testing proclivity between IBS experts and community providers.METHODS-We developed a survey to measure decision-making in two standardized patients with Rome III-positive IBS, including IBS with diarrhea (D-IBS) and IBS with constipation (C-IBS). The survey elicited provider knowledge and beliefs about IBS, including testing proclivity and beliefs regarding IBS as a diagnosis of exclusion. We surveyed nurse practitioners, primary care physicians, community gastroenterologists, and IBS experts.RESULTS-Experts were less likely than nonexperts to endorse IBS as a diagnosis of exclusion (8 vs. 72%; P < 0.0001). In the D-IBS vignette, experts were more likely to make a positive diagnosis of IBS (67 vs. 38%; P < 0.001), to perform fewer tests (2.0 vs. 4.1; P < 0.01), and to expend less money on testing (US$297 vs. $658; P < 0.01). Providers who believed IBS is a diagnosis of exclusion ordered 1.6 more tests and consumed $364 more than others (P < 0.0001). Experts only rated celiac CONFLICT OF INTERESTGuarantor of the article: Brennan M.R. Spiegel, MD, MSHS. Specific author contributions: Study design, study implementation, data collection, data analysis, data interpretation, paper preparation, and paper approval: Brennan Spiegel; study design, study implementation, data collection, and paper review: Mary Farid; study design, data interpretation, and paper review: Eric Esrailian; study implementation and data collection: Jennifer Talley; study design, data interpretation, paper preparation, and paper approval: Lin Chang. Potential competing interests: Spiegel and Chang have served as advisors to Prometheus Laboratories, and have received grant support from Takeda Sucampo Pharmaceuticals, Rose Pharmaceuticals, and Prometheus Laboratories. NIH Public Access Author ManuscriptAm J Gastroenterol. Author manuscript; available in PMC 2010 October 4. CONCLUSIONS-Most community providers believe IBS is a diagnosis of exclusion; this belief is associated with increased resource use. Experts comply more closely with guidelines to diagnose IBS with minimal testing. This disconnect suggests that better implementation of guidelines is warranted to minimize variation and improve cost-effectiveness of care.

Neither lamivudine nor adefovir monotherapy is cost-effective in chronic HBV infection. However, a hybrid salvage strategy reserving adefovir only for lamivudine-associated viral resistance may be highly cost-effective across most health care settings. Interferon therapy may still be preferred in health care systems with limited resources, especially in those serving populations with a high prevalence of HBeAg-negative HBV.

Both entecavir and adefovir are cost-effective in patients with HBV cirrhosis. Choosing between adefovir and entecavir is highly dependent on available budgets. In patients with HBV cirrhosis with previous lamivudine resistance, "adefovir salvage" appears more effective and less expensive than "entecavir salvage."