Modeling the Economic and Health Impact of Lowering the Recommended Colorectal Cancer Screening Age in Canada Using Fecal Immunochemical Test versus Colonoscopy
Bibliographic record
Abstract
BACKGROUND: The increasing rates of early-onset colorectal cancer in Canada suggest that earlier screening may be warranted. Canadian guidelines recommend biennial screening at 50 years of age with a fecal immunochemical test (FIT). METHODS: OncoSim was used to project the outcomes of revised colorectal cancer screening guidelines in Canada for four cohorts born between 1973 and 1992. Cohort risk ratios were calibrated to Canadian incidence data to reflect early-onset trends. We evaluated the incremental colonoscopy burden of earlier FIT screening and primary colonoscopy screening compared with a reference scenario screening with FIT biennially at 50 years of age (FIT 50). Sensitivity analyses were performed by adjusting screening participation and discount rates. RESULTS: FIT at 45 and 40 years of age (FIT 45 and FIT 40, respectively) increased the colonoscopy demand by 3.9% and 6.6%, respectively, over the lifetime of screening. Colonoscopy screening resulted in 89.0% to 116.7% more colonoscopies than FIT 50. Screening and total costs increased in all scenarios, but treatment costs decreased. FIT 45 and FIT 40 reduced the incidence by 103 and 161 and colorectal cancer deaths by 43 and 71 per 100,000, respectively. Colonoscopy screening led to 858 to 954 fewer cases and 260 to 303 fewer deaths per 100,000, resp. FIT 45and FIT 40 had incremental cost-effectiveness ratios of $5,850 per quality-adjusted life year (QALY) and $7,038 per QALY, respectively, compared with FIT 50. Colonoscopy scenarios had incremental cost-effectiveness ratios of $2,743 to $7,509 per QALY. CONCLUSIONS: Updated screening can reduce the colorectal cancer burden in younger populations. Increasing FIT screening with earlier initiation is more feasible logistically than increasing colonoscopy first approaches. IMPACT: These findings may inform future guideline revisions in Canada addressing early-onset colorectal cancer.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.007 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.003 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.009 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".