Impact of changing from annual to biennial mammographic screening on breast cancer outcomes in women aged 50–79 in British Columbia
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
OBJECTIVES: The objective of this study was to compare breast cancer outcomes among women subject to different policies on mammography screening frequency. SETTING: Data were obtained for women participating in the Screening Mammography Programme of British Columbia (SMPBC) for 1988--2005. The SMPBC changed its policy for women aged 50-79 years from annual to biennial mammography in 1997, but retained an annual recommendation for women aged 40-49 years. METHODS: Breast cancer outcomes were compared for women participating in the programme before and after 1997 for two groups: ages 40-49 and 50-79 years. RESULTS: There were data on 658,151 women. Comparing pre-1997 and post-1997, the median interscreen interval increased by 11.1 months in women 50-79 but by only 0.3 months in women aged 40-49. Excluding those detected at initial screen, 6291 breast cancers were identified. Comparing pre-1997 and post-1997: the relative rates (RR) of screen detected cancer increased in women aged 40-49 (RR = 1.32) and the rate of invasive cancers > or =20 mm at diagnosis decreased (RR = 0.83); the rate of cancers with axillary node involvement increased in women aged 50-79 (RR = 1.23). Cancer survival improved after 1997 for women diagnosed at ages 40-49 (hazard ratio = 0.62), but was unchanged for women aged 50-79. Breast cancer mortality rates did not change between the periods in either age group. CONCLUSION: The proximal cancer outcomes considered (staging and survival) improved in women aged 40-49 but this was offset in women aged 50-79 associated with the change in screen frequency. These changes did not result in alterations in breast cancer mortality rates in either age group.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 it