Stool DNA testing to screen for colorectal cancer in the medicare population: A cost-effectiveness analysis

Background: The Centers for Medicare & Medicaid Services considered whether to reimburse stool DNA testing for colorectal cancer screening among Medicare enrollees. Objective: To evaluate the conditions under which stool DNA testing could be cost-effective compared with the colorectal cancer screening tests currently reimbursed by the Centers for Medicare & Medicaid Services. Design: Comparative microsimulation modeling study using 2 independently developed models. Data Sources: Derived from literature. Target Population: A cohort of persons aged 65 years. A sensitivity analysis was also conducted, in which a cohort of persons aged 50 years was studied. Time Horizon: Lifetime. Perspective: Third-party payer. Intervention: Stool DNA test every 3 or 5 years in comparison with currently recommended colorectal cancer screening strategies. Outcome Measures: Life expectancy, lifetime costs, incremental cost-effectiveness ratios, and threshold costs. Results of Base-Case Analysis: Assuming a cost of $350 per test, strategies of stool DNA testing every 3 or 5 years yielded fewer life-years and higher costs than the currently recommended colorectal cancer screening strategies. Screening with the stool DNA test would be cost-effective at a per-test cost of $40 to $60 for stool DNA testing every 3 years, depending on the simulation model used. There were no levels of sensitivity and specificity for which stool DNA testing would be cost-effective at its current cost of $350 per test. Stool DNA testing every 3 years would be costeffective at a cost of $350 per test if the relative adherence to stool DNA testing were at least 50% better than that with other screening tests. Results of Sensitivity Analysis: None of the results changed substantially when a cohort of persons aged 50 years was considered. Limitation: No pathways other than the traditional adenoma-carcinoma sequence were modeled. Conclusion: Stool DNA testing could be a cost-effective alternative for colorectal cancer screening if the cost of the test substantially decreased or if its availability would entice a large fraction of otherwise unscreened persons to receive screening. Primary Funding Source: Agency for Healthcare Research and Quality.