Clinical Predictors for Venous Thromboembolism in Patients With a History of Thrombosis (PREDICTORS) (PREDICTORS)

Clinical Predictors for Venous Thromboembolism in Patients With a History of Thrombosis

Patients with a history of blood clots are at risk of developing additional clots in the future. Doctors use a tool called a clinical decision rule to tell them how likely it is that a patient has a blood clot and if they should have further testing to look for the clot. This tool may cause doctors to over-diagnosis a recurrent clot because the symptoms may be left over from the previous clot. Correctly diagnosing a recurrent blood clot is very important since there are risks associated with both over-diagnosis and under-diagnosis. If a recurrent blood clot is missed (under-diagnosis) the patient is at risk of death from a clot in the lungs. If blood thinners are prescribed when they are not needed (over-diagnosis), the patient may have to take blood thinners for their lifetime and risk having serious bleeding.

Study Overview

• Status: Completed
• Conditions: Deep Vein Thrombosis; Venous Thromboembolism; Pulmonary Embolism; Thromboembolic Disease Recurrent; Recurrent Thromboembolic Disease

Detailed Description

Several tools have been developed to standardize the diagnostic management of a suspected first blood clot. One of these tools is the use of a clinical decision rule. Clinical decision rules have been designed to help clinicians make diagnostic and therapeutic decisions at the bedside. A score is computed on the presence of some criteria from the patient's medical history, clinical signs and symptoms. The score provides the probability of a blood clot. The rules can be used in combinations with a simple blood test - called D-dimer - to identify patients at low risk who don't require diagnostic imaging testing. Benefits include reduced costs, length in hospital and radiation exposure.

Patients with prior blood clots have been shown to be less likely to benefit from the non-invasive testing. Therefore, they often need to undergo imaging tests, which are frequently difficult to interpret in patients with prior blood clots since residual clots are often present and are difficult to distinguish from a recurrent clot.

The objective of this study is to try to prospectively assess the role of existing clinical decision rules in patients with prior blood clots, and to attempt to improve them in order to increase the yield of non-invasive testing and to reduce the risk of over-diagnosis with imaging tests.

With respect to this study, clots within the deep veins of the legs are called deep vein thrombosis (DVT), while clots in the lungs are called pulmonary embolism (PE).

• Study Type: Observational
• Enrollment (Actual): 744

Contacts and Locations

Study Locations

• Canada
  • Nova Scotia
    • Halifax, Nova Scotia, Canada, B3H 1V7
      • Nova Scotia Health Authority
  • Ontario
    • Hamilton, Ontario, Canada, L8L 2X2
      • Hamilton Health Sciences Centre
    • London, Ontario, Canada, N6G 4A5
      • Lawson Health Research Institute
    • Ottawa, Ontario, Canada, K1H 8L6
      • The Ottawa Hospital
    • Ottawa, Ontario, Canada, K1K 0T2
      • Hôpital Montfort
    • Toronto, Ontario, Canada, M3M 0B2
      • Humber River Hospital
  • Quebec
    • Montreal, Quebec, Canada, H3T 1E2
      • Sir Mortimer B. Davis Jewish General Hospital
• Netherlands
  • Leiden, Netherlands
    • Leiden University Medical Centre
• Switzerland
  • Geneva, Switzerland
    • Geneva University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Outpatients presenting with suspected acute recurrent venous thromboembolism (VTE).

Description

Inclusion Criteria:

• Outpatients with clinically suspected acute recurrent DVT or PE regardless of whether the previous event was a DVT or PE
• Age ≥18 years old
• Willing and able to give informed consent

Exclusion Criteria:

• Life expectancy less than 3 months
• Suspicion of upper extremity thrombosis or thrombosis at an unusual site (e.g. cerebral or abdominal venous thrombosis)
• Previous VTE was distal DVT or subsegmental PE
• Suspected recurrent VTE is asymptomatic
• Previously enrolled in this study

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Validation of the Wells DVT Clinical Decision Rule	The Wells DVT Clinical Decision Rule (CDR) assigns a score from -2 to +9 based on clinical variables (e.g., active cancer, limb swelling, localized tenderness, prior history of DVT, alternative diagnosis as likely or more likely than DVT). In this study, the 3-level Wells DVT CDR was applied prospectively at presentation (Day 0) to participants with suspected recurrent DVT, using data collected from patient history and physical examination. Scores classify patients into low (≤0), moderate (1-2), or high (≥3) probability of DVT. Higher scores indicate greater probability of recurrent DVT. The outcome measure was the rate of confirmed recurrent DVT events within each Wells category, confirmed by objective imaging and adjudicated by an independent committee.	Day 0 (at time of suspected recurrent DVT)
Validation of the Wells PE Clinical Decision Rule	The 3-level Wells PE score (range 0-12.5) was calculated from history and exam at the index visit. Scores ≤4 = PE unlikely, >4 = PE likely. Higher scores indicate greater likelihood of PE. The outcome is the proportion with confirmed recurrent PE at the index diagnostic work-up, adjudicated by blinded review of imaging.	Day 0 (at time of suspected recurrent PE)
Validation of the Geneva PE Clinical Decision Rule	The revised Geneva score (range 0-22) was calculated from history and exam at the index visit. Scores 0-3 = low, 4-10 = intermediate, ≥11 = high probability. Higher scores indicate greater likelihood of PE. The outcome is the proportion with confirmed recurrent PE at the index diagnostic work-up, adjudicated by blinded review of imaging.	Day 0 (at time of suspected recurrent PE)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Accuracy of Current D-dimer Testing Methods	D-dimer testing at the index visit was performed using the institutional cut-off for positivity in place during the study period (2014-2019). Results were classified as positive or negative. The outcome is the proportion with confirmed recurrent VTE in each test category at the index diagnostic work-up, adjudicated by blinded review of imaging.	Day 0 (at time of suspected recurrent VTE)
Rate of Confirmed Events Using Current Wells DVT/Wells PE/Geneva PE in Participants on Anticoagulant Therapy	The Wells DVT, Wells PE, and Geneva PE scores were calculated at the index visit in participants on anticoagulation. Score ranges and cut-offs as per respective rules. The outcome is the proportion with confirmed recurrent VTE in each risk category at the index diagnostic work-up, adjudicated by blinded review of imaging.	Day 0 (at time of suspected recurrent VTE)
All-Cause Mortality Within 90 Days of Index Visit	Number of participants who died from any cause from enrollment (Day 0) through Day 90 follow-up for those without confirmed recurrent VTE at enrollment.	From enrollment (Day 0) through Day 90 follow-up for those not diagnosed with a confirmed recurrent VTE at enrollment

Collaborators and Investigators

• Sponsor: Ottawa Hospital Research Institute
• Investigators: Principal Investigator: Gregoire Le Gal, MD, Ottawa Hospital

Publications and helpful links

General Publications

• Mai V, Martens ESL, Righini M, Schulman S, Thiruganasambandamoorthy V, Kahn SR, Pecarskie A, Kovacs MJ, Visser S, Shivakumar S, Tan M, Kearon C, Rodger M, Scarvelis D, Delluc A, Girard P, Huisman MV, Wells PS, Klok FA, Le Gal G; PREDICTORS study group. Performance of clinical decision rules in patients presenting with suspected recurrent venous thromboembolism: a multicenter prospective cohort study. J Thromb Haemost. 2025 Jun 25:S1538-7836(25)00408-8. doi: 10.1016/j.jtha.2025.06.019. Online ahead of print.

Study record dates

Study Major Dates

• Study Start (Actual): November 19, 2014
• Primary Completion (Actual): January 3, 2019
• Study Completion (Actual): January 3, 2019

Study Registration Dates

• First Submitted: October 15, 2014
• First Submitted That Met QC Criteria: November 18, 2014
• First Posted (Estimated): November 21, 2014

Study Record Updates

• Last Update Posted (Estimated): September 5, 2025
• Last Update Submitted That Met QC Criteria: September 3, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Respiratory Tract Diseases; Lung Diseases; Embolism and Thrombosis; Embolism; Thrombosis; Pulmonary Embolism; Venous Thrombosis; Thromboembolism; Venous Thromboembolism
• Other Study ID Numbers: 20140622-01H

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No