Systematic review of venous thromboembolism (VTE) occurrence in hospitalized patients receiving prophylactic unfractionated heparin twice vs. three times daily
Bibliographic record
Abstract
Guidelines recommend 5000U subcutaneous unfractionated heparin (UFH) for venous thromboembolism (VTE) prophylaxis in acutely ill hospitalized adults, but data comparing dosing frequencies is limited. This systematic review aimed to compare VTE and bleeding outcomes between twice daily (BID) and three times daily (TID) UFH regimens. A literature search was completed on 3/7/2024. The primary outcome was VTE occurrence (deep vein thrombosis (DVT) or pulmonary embolism (PE)). Secondary outcomes included bleeding events. Studies reporting any relevant outcomes were included, while non-human studies, reviews, non-English texts, and high VTE risk populations were excluded. Risk of bias was assessed using the Cochrane Risk-of-Bias or Newcastle-Ottawa Quality Assessment Form. Data were synthesized using Covidence and Excel. After screening, 24 studies were included: 9 observational and 15 randomized studies. Regimens with TID UFH had a 3.1% VTE occurrence (12 studies, n = 145/4653) compared to 4.0% with BID regimens (9 studies, n = 218/5426). Three times daily regimens demonstrated 4.8% DVTs (11 studies, n = 244/5102) and 0.4% PEs (11 studies, n = 24/5372), compared to 9.7% DVTs (11 studies, n = 199/2062) and 0.9% PEs (9 studies, n = 17/1974) with BID regimens. Bleeding events occurred in 3.2% of patients with BID (9 studies, n = 196/6080) and 4.3% with TID regimens (13 studies, n = 393/9044). Three times daily UFH regimens led to fewer VTE, DVT, and PE events but more bleeding compared to BID. Newer data suggests BID dosing may be more appropriate for general medical populations. Limitations include variability in data quality and publication dates. Registered with PROSPERO. No funding was received.
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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 | 0.010 | 0.037 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.013 | 0.010 |
| Bibliometrics | 0.012 | 0.012 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 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".