Cost-effectiveness analysis of optimal diagnostic strategy for patients with symptomatic cholelithiasis with...

EUS, MRCP, and intraoperative cholangiogram (IOC) are the recommended diagnostic modalities for patients with intermediate probability for choledocholithiasis (IPC). The relative cost-effectiveness of these modalities in patients with cholelithiasis and IPC is understudied.

We developed a decision tree for diagnosing IPC (base-case probability, 50%; range, 10%-70%); patients with a positive test were modeled to undergo therapeutic ERCP. The strategies tested were laparoscopic cholecystectomy with IOC (LC-IOC), MRCP, single-session EUS + ERCP, and separate-session EUS + ERCP. Costs and probabilities were extracted from the published literature. Effectiveness was assessed by assigning utility scores to health states, average proportion of true-positive diagnosis of IPC, and the mean length of stay (LOS) per strategy. Cost-effectiveness was assessed by extrapolating a net-monetary benefit (NMB) and average cost per true-positive diagnosis.

LC-IOC was the most cost-effective strategy to diagnose IPC (base-case probability of 50%) among patients with cholelithiasis in health state-based effectiveness analysis (NMB of $34,612), diagnostic test accuracy-based effectiveness analysis (average cost of $13,260 per true-positive diagnosis), and LOS-based effectiveness analysis (mean LOS of 4.13) compared with strategies 2 (MRCP), 3 (single-session EUS + ERCP), and 4 (separate-session EUS + ERCP). These findings were robust on deterministic and probabilistic sensitivity analyses.

For patients with cholelithiasis with IPC, LC-IOC is a cost-effective approach that should limit preoperative testing and may shorten hospital LOS. Our findings may be used to design institutional and organizational management protocols.