Evidence-based decision analysis guiding clinical guidelines for an organized population-based screening for colorectal cancer.

BACKGROUND

This study includes the long-term benefit-harm analysis of population-wide colorectal cancer (CRC) screening strategies commissioned by the Austrian National Committee for Cancer Screening (ANCCS). In addition, we present the related cost-effectiveness analysis.

METHODS

Using a validated decision-analytic Markov state transition model, we evaluated 17 by the ANCCS suggested CRC-screening strategies differing in tests (fecal-immunochemical test (FIT), guaiac-based fecal occult blood test (gFOBT), colonoscopy (COL)), age at start (40,45,50 years) and end (COL: 65,70,75 years, FIT/gFOBT 75 years), and intervals (2,5,10 years). Positive FIT/gFOBT tests are followed by colonoscopy. Evaluated outcomes included health benefits (life-years gained (LYG), CRC-cases/CRC-deaths avoided), harms (severe colonoscopy complications, psychological harms due to positive test results (PTR), additional colonoscopies), stepwise evaluated incremental harm-benefit ratios (IHBR), and incremental cost-effectiveness ratios (ICER). We applied the Austrian healthcare system perspective, a lifelong-time horizon and conducted sensitivity analyses.

RESULTS

The most effective colonoscopy-based screening strategy is colonoscopy at age 40/50/60/70 (449 LYG per 1000 individuals) with an IHBR of 3 PTR/LYG compared to COL45/55/65 (ICER: 13,032 Euro/LYG vs. COL45/55/65/75). The most effective fecal blood-test-based strategy is annual FIT testing starting at age 40 years (488 LYG per 1000 individuals) and an IHBR of 30 PTR/LYG compared to FIT40+2y (biennial FIT starting age 40). All biennial FIT-based screening strategies represent alternative options on the harm-benefit efficiency frontier with IHBR of PTR/LYG: 2 (FIT50+2y vs. no screening), 5 (FIT45+2y vs. FIT50+2y), and 7 (FIT40+2y vs. FIT45+2y). The cost-effectiveness analyses provided stepwise ICERs ranging from 3391 Euro/LYG (FIT45+2y vs. FIT50+2y) to 47,812 Euro/LYG (FIT40+1y vs. FIT40+2y).

CONCLUSIONS

Our decision analysis shows benefit-harm and cost-effectiveness trade-offs. In the consensus meeting of the ANCCS, colonoscopy- and FIT-based screening starting at age 45 were selected as suggested screening strategies, accounting for benefit-harm balance, evidence level, and implementation aspects.