Effect of dementia on 1‐year mortality in subdural hematoma: a preliminary analysis
Bibliographic record
Abstract
BACKGROUND: Aging and brain atrophy are risk factors for subdural hematoma (SDH). This preliminary analysis aims to quantify the effect of living with dementia on 1-year mortality following hospital admission for SDH. METHOD: Medical record data between Dec 2021 and Jan 2023 were reviewed retrospectively with a sampling rate of 1:2 (with dementia: without dementia) for participants with SDH managed conservatively. Propensity score matching (PSM) was used to estimate the average marginal effect of living with dementia on 1-year mortality, accounting for covariates (age, sex, chronicity of SDH, average hematoma width, midline shift). We used a 1:1 nearest neighbour PSM without replacement with propensity scores estimated using logistic regression of dementia status on covariates. Risk Ratio (RR) with 95% confidence intervals (CI) is reported from logistic regression after PSM to evaluate the association between dementia (as the sole predictor due to a low event rate <10) and 1-year mortality, with statistical significance considered at p < 0.05. RESULT: A total of 54 adults with a mean age of 77±15 were included, 50% (27/60) being men, 39% (21/54) having dementia, and 7.4% (4/54) having chronic SDH. The 1-year mortality rate was approximately twice in those living with dementia, 19% (4/21) vs. without 9.1% (3/33) (Cramer V = .14, df = 1, N = 54). After PSM, 12 non-dementia cases were excluded, and all covariate differences were 0.3, indicating an acceptable balance for preliminary analysis. The effect of dementia on 1-year mortality is as follows: RR = 1.33, 95% CI [0.28, 6.18], p = 0.713, N = 42. CONCLUSION: 1-year mortality appears 33% more likely in the dementia cohort, but the confidence interval is too wide to be conclusive. A sample size of 154 is needed for sufficient power (1-β=0.80, α=0.05) and to include covariates with an absolute std. mean difference of > 0.1 after PSM. Additional information: Funded by the Canadian Institutes of Health Research Micheal Smith Foreign Study Supplement (Funding reference number: FSS - 191081).
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How this classification was reachedexpand
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".