Risk-stratified versus Non-Risk-stratified Diagnostic Testing for Management of Suspected Acute Biliary Obstruction: Comparative Effectiveness, Costs, and the Role of MR Cholangiopancreatography.

Abstract

Purpose To analyze the cost-effectiveness of the American Society for Gastrointestinal Endoscopy (ASGE) risk stratification guidelines versus magnetic resonance (MR) cholangiopancreatography-based treatment of patients with possible choledocholithiasis. Materials and Methods A decision-analytic model was constructed to compare cost and effectiveness of three diagnostic strategies for gallstone disease with possible choledocholithiasis: noncontrast MR cholangiopancreatography, contrast material-enhanced MR imaging/MR cholangiopancreatography, and ASGE risk stratification guidelines for diagnostic evaluation recommending endoscopy (high risk), MR cholangiopancreatography (intermediate risk), or no test (low risk). Analysis was performed from a U.S. health system perspective over 1-year and lifetime horizons. The model accounted for benign and malignant causes of biliary obstruction and procedural complications. Cost information was based on Medicare reimbursements. Sensitivity analysis assessed the impact of parameter variability on model results. Results Noncontrast MR cholangiopancreatography was most cost-effective in 45-55-year-old patients (less than $100 000 per quality-adjusted life-year [QALY] gained), while contrast-enhanced MR imaging was favored in younger adults. Risk-stratified testing was less costly than MR cholangiopancreatography, with long-term savings of $1870 and $2068 versus noncontrast and contrast-enhanced MR cholangiopancreatography, respectively, but was also less effective (-0.1814, -0.1831 QALY, respectively). The lifetime incremental cost per QALY for noncontrast MR cholangiopancreatography was $10 311. Contrast-enhanced MR imaging was favored with pretest probabilities of biliary stricture or malignancy 0%-73% for patients aged 20-44 years. For patients older than 55 years, ASGE guidelines maximized QALYs at the lowest cost. Conclusion Although adults older than 55 years of age are optimally evaluated by using ASGE guidelines, younger patients suspected of having acute biliary obstruction likely benefit from MR cholangiopancreatography rather than risk-stratified diagnostic imaging because of improved detection of choledocholithiasis and alternative causes of biliary obstruction. © RSNA, 2017 Online supplemental material is available for this article.