Percutaneous liver biopsy: a cost-benefit analysis comparing sonographic and CT guidance.

OBJECTIVE We compared the relative cost of a liver biopsy performed with sonographic guidance with that of one performed with CT guidance in a cost-benefit analysis model. MATERIALS AND METHODS Variables were estimated from a search of the literature and from clinical experience with 437 hepatic biopsies at our institution. Probability variables included the probability of obtaining an adequate sample and the probability of a major complication. Cost variables included the direct and indirect costs, the cost of a major complication, and the opportunity costs of foregone revenue from preempted diagnostic studies. One-way and two-way sensitivity analyses were performed. RESULTS Using baseline values, CT guidance was 1.89 times more expensive than sonographic guidance. Sensitivity analyses indicate that CT and sonographic guidance costs would be equivalent if the success rate with sonographic guidance was 39.8%, the opportunity costs of CT guidance were 3.13 times less than best estimates, and the opportunity costs of sonography were 3.15 times greater than best estimates. CONCLUSION Sonographic guidance for hepatic biopsies is substantially more economical than CT guidance across a wide range of estimated costs.