Cost-Effectiveness Analysis of Endoscopic Ultrasound versus Magnetic Resonance Cholangiopancreatography in Patients with Suspected Common Bile Duct Stones

Background Patients with suspected common bile duct (CBD) stones are often diagnosed using endoscopic retrograde cholangiopancreatography (ERCP), an invasive procedure with risk of significant complications. Using endoscopic ultrasound (EUS) or Magnetic Resonance CholangioPancreatography (MRCP) first to detect CBD stones can reduce the risk of unnecessary procedures, cut complications and may save costs. Aim This study sought to compare the cost-effectiveness of initial EUS or MRCP in patients with suspected CBD stones. Methods This study is a model based cost-utility analysis estimating mean costs and quality-adjusted life years (QALYs) per patient from the perspective of the UK National Health Service (NHS) over a 1 year time horizon. A decision tree model was constructed and populated with probabilities, outcomes and cost data from published sources, including one-way and probabilistic sensitivity analyses. Results Using MRCP to select patients for ERCP was less costly than using EUS to select patients or proceeding directly to ERCP ($1299 versus $1753 and $1781, respectively), with similar QALYs accruing to each option (0.998, 0.998 and 0.997 for EUS, MRCP and direct ERCP, respectively). Initial MRCP was the most cost-effective option with the highest monetary net benefit, and this result was not sensitive to model parameters. MRCP had a 61% probability of being cost-effective at $29,000, the maximum willingness to pay for a QALY commonly used in the UK. Conclusion From the perspective of the UK NHS, MRCP was the most cost-effective test in the diagnosis of CBD stones.