New tool for diagnosing pulmonary embolism in emergency departments

Emergency Medicine Pulmonary Embolism Testing Multicentre Study

Observational Queen's University · NCT06320236

This study is testing a new tool to help emergency doctors decide when imaging for pulmonary embolism is really needed, aiming to reduce unnecessary scans and radiation exposure for patients.

Quick facts

Study typeObservational
Enrollment4000 (estimated)
Ages18 Years and up
SexAll
SponsorQueen's University Academic / other
Drugs / interventionsradiation
Locations4 sites (Hamilton, Ontario and 3 other locations)
Trial IDNCT06320236 on ClinicalTrials.gov

What this trial studies

This observational study aims to evaluate the effectiveness of the Adjust-Unlikely clinical decision rule in reducing unnecessary imaging for pulmonary embolism (PE) in emergency department patients. The Adjust-Unlikely tool, developed by a team of researchers and emergency physicians, is designed to be highly sensitive and user-friendly for emergency settings. By implementing this decision rule, the study seeks to minimize the exposure of patients to radiation and reduce healthcare costs associated with unnecessary imaging. The study will involve patients who are tested for PE in emergency departments across Canada.

Who should consider this trial

Good fit: Ideal candidates for this study are emergency department patients being tested for pulmonary embolism.

Not a fit: Patients who have had recent imaging for PE or deep vein thrombosis, or those with other contraindications, may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could significantly decrease unnecessary imaging for pulmonary embolism, improving patient safety and reducing healthcare costs.

How similar studies have performed: Other studies have shown promise in using clinical decision rules to reduce unnecessary imaging, making this approach both relevant and potentially impactful.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Emergency department patient who is tested by an emergency physician for PE

Exclusion Criteria:

* Patient is \< 18 years of age
* No documentation of whether PE is the most likely diagnosis
* D-dimer is not tested or else not resulted during the emergency visit
* The D-dimer level is known before documentation of whether PE is the most likely diagnosis
* The D-dimer is ordered prior to the physician assessing the patient
* The patient has previously registered that they opt out of all research at the participating site
* The patient leaves against medical advice
* The patient has had PE or deep vein thrombosis imaging (CT pulmonary angiogram, ventilation-perfusion scan or lower limb ultrasound) within prior 30 days
* There is a new (non-PE) indication for anticoagulation
* The patient was initiated on treatment for presumed PE prior to PE testing
* The patient has previously been enrolled into the study
* The patient has a prior history of lower extremity deep vein thrombosis without availability of a baseline ultrasound scan
* The patient was transferred from another hospital organization
* The patient does not reside in Ontario
* The patient has no valid Ontario Health Insurance Plan card

Where this trial is running

Hamilton, Ontario and 3 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Pulmonary EmbolismD-dimerDiagnosisAdjust-UnlikelyDiagnosticEmergency Medicine
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.