Cost-Effectiveness of Alternative Imaging Strategies for the Diagnosis of Small-bowel Crohn's Disease

BACKGROUND AND AIMS:: The cost-effectiveness of alternative approaches to the diagnosis of small-bowel Crohn's disease is unknown. This study evaluates whether CT-Enterography (CTE) is a cost-effective alternative to small bowel follow-through (SBFT) and whether capsule endoscopy is a cost-effective third test in patients in whom a high suspicion of disease remains after two previous negative tests.

METHODS:: A decision-analytic model was developed to compare the lifetime costs and benefits of each diagnostic strategy. Patients were considered with low (20%) and high (75%) pretest probability of small-bowel Crohn's disease. Effectiveness was measured in quality-adjusted life-years (QALYs) gained. Parameter assumptions were tested with sensitivity analyses. RESULTS:: With a moderate to high pretest probability of small-bowel Crohn's disease, and higher likelihood of isolated jejunal disease, follow-up with CTE has an incremental cost-effectiveness ratio of less than $54,000/QALY-gained compared to SBFT. The addition of capsule endoscopy after ileocolonoscopy and negative CTE or SBFT costs greater than $500,000 per QALY-gained in all scenarios. Results were not sensitive to costs of tests or complications and were sensitive to test accuracies.

CONCLUSIONS:: The cost-effectiveness of strategies depends critically on the pretest probability of Crohn's disease and if the terminal ileum is examined at ileocolonoscopy. CTE is a cost-effective alternative to SBFT in patients with moderate to high suspicion of small-bowel Crohn's disease. The addition of capsule endoscopy as a third test is not a cost-effective third test even in patients with high pretest probability of disease.