Adjust-Unlikely: Pulmonary embolism will be excluded during emergency department assessment by the combination of: 1. 'Pulmonary embolism is the most likely diagnosis' as per the treating physician AND a D-dimer result \< 500 ug/L fibrinogen equivalent units; 2. 'Pulmonary embolism is not the most likely diagnosis' AND D-dimer \< age-adjusted threshold; or, 3. A negative computed tomography scan, planar ventilation perfusion scan or ventilation perfusion-SPECT. Emergency departments will use their local laboratory D-dimer assay.
It is important to diagnose pulmonary embolism in a timely manner to prevent death and long-term disability. More than half a million people (4-5% of emergency department patients) are tested for pulmonary embolism, although the positive rate is low. Imaging for PE testing exposes patients to radiation, is expensive, adds time to the emergency visit, and can lead to a false positive diagnoses. Existing protocols aimed at reducing unnecessary pulmonary embolism imaging are complex and seldom used by emergency physicians. Too many patients undergo unnecessary pulmonary embolism imaging.
A new tool (called Adjust-Unlikely) could safely reduce pulmonary embolism imaging in Canada. A research group composed of researchers, emergency physicians, and patients developed the Adjust-Unlikely clinical decision rule: a rule which has been customized for emergency physicians and emergency patients. Adjust-Unlikely is highly sensitive at the bedside, meaning there are very few false negative results.
The study aim is to prospectively validate Adjust-Unlikely pulmonary embolism testing in emergency patients with suspected pulmonary embolism.
| Facility | City | Region | Status |
|---|---|---|---|
| Hamilton Health Sciences Corporation | Hamilton | Ontario | Recruiting |
| Kingston Health Sciences Centre | Kingston | Ontario | Recruiting |
| London Health Sciences Centre Research Inc | London | Ontario | Active Not Recruiting |
| Ottawa Hospital Research Institute | Ottawa | Ontario | Active Not Recruiting |
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
View NCT06320236 on ClinicalTrials.gov ↗ ← All trials in Canada