Applying the Ottawa subarachnoid haemorrhage rule on a cohort of emergency department patients with headache
Bibliographic record
Abstract
OBJECTIVE: The Ottawa subarachnoid haemorrhage (SAH) rule suggests that alert patients older than 15 years with a severe nontraumatic headache reaching maximum intensity within 1 h and absence of high-risk variables effectively have a SAH ruled out. We aimed to determine the proportion of emergency department (ED) patients with any headache fulfilling the entry criteria for the Ottawa SAH rule. PATIENTS AND METHODS: The Ottawa SAH rule was applied retrospectively in a substudy of a prospective snapshot of 34 EDs in Queensland, Australia, carried out over 4 weeks in September 2014. Patient aged 18 years and older with a nontraumatic headache of any potential cause were included. Clinical data and results of investigations were collected. RESULTS: Data were available for 644 (76%) patients. A total of 149 (23.1%, 95% confidence interval: 20.0-26.5%) fulfilled and 495 (76.9%, 95% confidence interval: 73.5-80.0%) did not fulfil the entry criteria. In patients who fulfilled the entry criteria, 30 (<5% overall) did not have any high-risk variables for SAH. In patients who fulfilled the entry criteria and had at least 1 high-risk feature, almost half (46%) received a computed tomographic brain. No SAH were missed. CONCLUSION: In this descriptive observational study, the majority of ED patients presenting with a headache did not fulfil the entry criteria for the Ottawa SAH rule. Less than 5% of the patients in this cohort could have SAH excluded on the basis of the rule. More definitive studies are needed to determine an accepted benchmark for the proportion of patients receiving further work-up (computed tomographic brain) after fulfilling the entry criteria for the Ottawa SAH rule.
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 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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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) | 0.001 | 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 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".