Why are stroke patients excluded from TPA therapy?
Bibliographic record
Abstract
BACKGROUND: Thrombolytic therapy for acute stroke (<3 hours) will not have a major impact on death and dependency unless it is accessible to more patients. OBJECTIVE: To determine why patients with ischemic stroke did not receive IV TPA and assess the availability of this therapy to patients with ischemic stroke. METHODS: Consecutive patients with acute ischemic stroke were prospectively identified at a university teaching hospital between October 1996 and December 1999. Additional patients with ischemic stroke were identified that were admitted to one of three other hospitals in the Calgary region during the study period. The Oxford Community Stroke Programme Classification was used to record type and side of stroke. RESULTS: Of 2165 stroke patients presenting to the university hospital, 1168 (53.9%) were diagnosed with ischemic stroke, 31.8% with intracranial hemorrhage (intracerebral, subarachnoid, or subdural), and 13.9% with TIA. Delay in presentation to emergency department beyond 3 hours excluded 73.1% (854/1168). Major reasons for delay included uncertain time of onset (24.2%), patients waited to see if symptoms would improve (29%), delay caused by transfer from an outlying hospital (8.9%), and inaccessibility of treating hospital (5.7%). Twenty-seven percent of patients with ischemic stroke (314/1168) were admitted within 3 hours of sympton onset and of these 84 (26.7%) patients received IV TPA. The major reasons for exclusion in this group of patients (<3 hours) were mild stroke (13.1%), clinical improvement (18.2%), perceived protocol exclusions (13.6%), emergency department referral delay (8.9%), and significant comorbidity (8.3%). Of those patients who were considered too mild or were documented to have had significant improvement, 32% either remained dependent at hospital discharge or died during hospital admission. Throughout the region there was a total of 1806 ischemic stroke patients (admitted to all four Calgary hospitals). During this study period, 4.7% received IV TPA. CONCLUSIONS: The majority of patients are unable to receive TPA for acute ischemic stroke because they do no not reach the hospital soon enough. Of those patients presenting within 3 hours, 27% received the therapy but a further 31% were excluded because their symptoms were either considered too mild or were rapidly improving. Subsequently, a third of these patients were left either dependent or dead, bringing into question the initial decision not to treat.
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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 | 0.001 | 0.018 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".