Cost-effectiveness of nonmelanoma skin cancer screening in Crohn's disease patients.

Background: Several studies have demonstrated an increased risk of nonmelanoma skin cancer (NMSC) in patients with inflammatory bowel disease, with the greatest risk in patients with Crohn's disease (CD). We investigated the cost-effectiveness of NMSC screening in patients with CD.

Methods: A mathematical model was used to compare lifetime costs, life expectancies, and benefits of NMSC screening in a hypothetical cohort of 100,000 patients with CD. Strategies studied include: (1) Treat NMSC cases as they present and follow affected patients annually; (2) Screen patients with CD annually once they turn 50 years old, treat NMSC cases as they present and follow affected patients annually; (3) Screen patients with CD annually once they start receiving thiopurines, treat NMSC cases as they present and follow affected patients annually; (4) Screen patients with CD annually when they turn 50 years old or start receiving thiopurines, treat NMSC cases as they present, and follow affected patients annually; (5) Screen all patients with CD annually. These strategies were then studied on a biennial basis, accounting for 10 competing strategies.

Results: Screening all patients with CD annually proved the most cost-effective strategy with an average lifetime cost of more than $333,000, a quality-adjusted life expectancy of about 26 QALYs (95% confidence interval: 22-29), ICER of $3263/QALY, and led to early detection of about 94% of incident NMSC cases. The next best strategy was screening all CD patients biennially with an average lifetime cost of more than $328,000 with 24.5 QALYs (95% confidence interval: 21-25). Only 47% of new NMSC cases were detected early with this strategy.

Conclusion: At a willingness-to-pay threshold of $50,000, screening all patients with CD annually for NMSC proved the most cost-effective strategy.