Can colonoscopy remain cost-effective for colorectal cancer screening? The impact of practice patterns and the Will Rogers phenomenon on costs

Am J Gastroenterol. 2013 Mar;108(3):296-301. doi: 10.1038/ajg.2012.195. Epub 2012 Dec 4.

Abstract

Objectives: The adenoma detection rate (ADR) in screening colonoscopy is higher than original cost-effectiveness models estimated. Future colorectal cancer (CRC) risk is decreased once the ADR is 20%, but it is unclear how much additional protection is provided with higher ADRs. We modeled the impact of a high ADR on future CRC risk and surveillance colonoscopy burden.

Methods: We created three hypothetical scenarios for 100,000 average-risk individuals undergoing screening colonoscopy at age 50: (i) 20% ADR with 30% future CRC risk reduction; (ii) 50% ADR with 30% future CRC risk reduction; and (iii) 50% ADR with 50% future CRC risk reduction. After colonoscopy, patients could have high-risk or low-risk adenomas, or no adenomas.

Results: When the ADR increases from 20% to 50% but no additional CRC cases are prevented, future CRC risk for each group is still reduced, because lower-risk patients migrate into apparently higher-risk groups (the Will Rogers phenomenon). Future risk is further reduced if a 50% ADR leads to greater protection from CRC. However, despite the reductions in group-specific and overall future CRC risk, 34,635 additional surveillance colonoscopies are performed before the cohort is 60 years old when the ADR is 50% compared with 20%.

Conclusions: If current surveillance practices continue along with high ADRs, screening colonoscopy may not remain cost-effective.

MeSH terms

  • Adenoma / diagnosis*
  • Adenoma / economics
  • Colonoscopy / economics*
  • Colorectal Neoplasms / diagnosis*
  • Colorectal Neoplasms / economics
  • Cost-Benefit Analysis
  • Early Detection of Cancer / economics*
  • Female
  • Health Care Costs
  • Humans
  • Male
  • Middle Aged
  • Practice Patterns, Physicians' / economics*