International comparison of the cost-effectiveness of 5 years letrozole or anastrozole compared to 5 years tamoxifen for early breast cancer in hormone receptor-positive postmenopausal women: Belgium, Canada, UK, and US analyses
Bibliographic record
Abstract
556 Background: The BIG1–98 and ATAC trials have proven the effectiveness of 5 years letrozole (LET) and anastrozole (ANA), respectively, compared to 5 years tamoxifen (TAM) for the treatment of postmenopausal women with hormone receptor positive (HR+) early stage breast cancer. This analysis uses similar assumptions to those used in the NICE appraisal in the UK, and country specific input data to estimate the cost-effectiveness of LET vs TAM and ANA vs. TAM from the Belgian, Canadian, UK, and US health care perspective (8 analyses). Methods: The same Markov model was used to estimate the incremental cost per quality-adjusted life year (QALY) gained (ICQ) across the 8 analyses in postmenopausal women with HR+ early stage breast cancer. Model events and assumptions were based on the analysis undertaken by the NICE appraisal team in the UK. Probabilities of breast cancer events (contralateral; locoregional; and metastases) were based on the latest early breast cancer (Lancet) overview. Country-specific cost, utility, and adverse event parameter values were informed by relevant population-based studies. LET and ANA effects were informed by published results of the BIG 1–98 and ATAC trials, which were assumed to cease after therapy discontinuation (other than fracture risk that continued for 5 further years). Costs and QALYs were estimated over the remaining lifetime of a cohort of HR+ women aged 60 yrs, discounted at 3.5% annually. Conclusion: Compared to TAM, adjuvant treatment of postmenopausal HR+ women with LET or ANA for 5 years is a cost-effective use of resources in all of the countries included in this analysis. Based on the model assumptions used by the NICE appraisal team in the UK, the mean results indicate that LET is more cost-effective than ANA, though the confidence intervals are wide. [Table: see text] No significant financial relationships to disclose.
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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 | 0.009 | 0.024 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.003 | 0.008 |
| Bibliometrics | 0.002 | 0.003 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".