Sex differences in the incidence and prevalence of young‐onset Alzheimer's disease: A meta‐analysis
Bibliographic record
Abstract
Abstract Objectives The lifetime incidence of Alzheimer's disease is higher in women than in men, but it remains unclear if similar sex differences exist in young‐onset Alzheimer's disease (YOAD). This systematic review test the hypothesis that women have a higher prevalence and incidence of YOAD than men. Methods We searched Pubmed and Embase (inception to 11 June 2020) for original publications of population‐based observational studies with data on the prevalence and/or incidence of YOAD, defined as a medical diagnosis of Alzheimer's disease before the age of 65 years. Data on cross‐sectional and/or prospective numbers, percentages, incidences, and incidence rates (in person‐years) were derived from included studies. Quality assessment was done using the Nottingham Ottawa Scale. Meta‐analyses were done to test the hypothesis that women have a higher prevalence and incidence of YOAD than men. Results After screening of 3252 titles, 12 articles were included. The pooled prevalence was 0.4% (confidence interval [CI] = 0.1–2.1) in women and 0.2% (CI = 0–1.2) in men (six studies, relative risk [RR] = 1.54, CI = 0.69–3.44, I2 = 38%). The pooled incidence was 0.02% (CI = 0.01–0.08) in women and 0.01% (CI = 0–0.05) in men (five studies, RR = 1.50, CI = 0.91‐2.48, I2 = 0%). The incidence rates per 100,000 person‐years ranged from 0 to 132 in women and from 0 to 42 in men. Conclusions Given the low prevalence and wide CIs, no firm conclusions can be drawn. Large‐scale studies are required to verify that women are more likely than men to develop YOAD.
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.
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 | 0.015 | 0.032 |
| Meta-epidemiology (narrow) | 0.003 | 0.002 |
| Meta-epidemiology (broad) | 0.019 | 0.059 |
| Bibliometrics | 0.004 | 0.005 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.004 | 0.002 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.002 |
| 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".