Do Decision-Analytic Models Identify Cost-Effective Treatments? A Retrospective Look at Helicobacter Pylori Eradication

BACKGROUND: Pharmacoeconomic models of Helicobacter (H) pylori eradication have been frequently cited but never validated. OBJECTIVES: Examine retrospectively whether H pylori pharmacoeconomic models direct decision makers to cost-effective therapeutic choices. METHODS: We first replicated and then validated 2 models, replacing model assumptions with empirical data from a multipayer claims database. Database subjects were 435 commercially insured U.S. patients treated with bismuthme tronidazole-tetracycline (BMT), proton pump inhibitor (PPI)-clarithromycin, or PPI-amoxicillin. Patients met greater than1 clinical requirement (ulcer disease, gastritis/duodenitis, stomach function disorder, abdominal pain, H pylori infection, endoscopy, or H pylori assay). Sensitivity analyses included only patients with ulcer diagnosis or gastrointestinal specialist care. Outcome measures were: (1) rates of eradication retreatment; (2) use of office visits, hospitalizations, endoscopies, and antisecretory medication; and (3) cost per effectively treated (nonretreated) patient. RESULTS: Model results overstated the cost-effectiveness of PPI-clarithromycin and underestimated the cost-effectiveness of BMT. Prior to empirical adjustment, costs per effectively treated patient were $1,001, $980, and $1,730 for BMT, PPI clarithromycin, and PPI-amoxicillin, respectively. Estimates after adjustment were $852 for BMT, $1,118 for PPI-clarithromycin, and $1,131 for PPI-amoxicillin. Key model assumptions that proved retrospectively incorrect were largely unsupported by either empirical evidence or systematic assessment of expert opinion. CONCLUSIONS: Organizations with access to medical and pharmacy claims databases should test key assumptions of influential models to determine their validity. Journal peer-review processes should pay particular attention to the basis of model assumptions.