Blood Clot/DVT prediction rules (deep vein thrombosis)

Blood Clot/DVT Evidence predictor rules

The picture above is from the website: The red and swollen leg in the picture above has a blood clot. 

If you think you may have a  blood clot (even if it is low risk) you need to go to the Emergency Room immediately /or call 911 because it could be fatal. The blood clot could travel from your leg or groin to the lungs and kill you. The ER clinicians will likely do a d dimer test or a venous ultrasound to rule out a blood clot.  If you have a clot your physician may give you blood thinners if it is appropriate.  Here is the evidence for clinicians and patients to get a better understanding of blood clot predictors.  It usually occurs in the calf or inner thigh or groin region when the leg is inactive.  Below is a chart (according to the evidence) to help see the predictors for a blood clot.



Wells Clinical Prediction Rule for DVT


Active cancer (treatment within 6 months, or palliation)


Paralysis, paresis, or immobilization of lower extremity


Bedridden for more than 3 days because of surgery (within 4 weeks)


Localized tenderness along distribution of deep veins


Entire leg swollen


Unilateral calf swelling of greater than 3 cm (below tibial tuberosity)


Unilateral pitting edema


Collateral superficial veins


Alternative diagnosis as likely as or more likely than DVT


Total points:

DVT = deep venous thrombosis. (blood clot)

Risk score interpretation (probability of DVT): 3 points: high risk (75%); 1 to 2 points: moderate risk (17%);<1 point: low risk (3%).

Adapted with permission from Wells PS, Anderson DR, Bormanis J, Guy F, Mitchell M, Gray L, et al. Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet 1997;350:1796.



5 thoughts on “Blood Clot/DVT prediction rules (deep vein thrombosis)

  1. My husband should have known about that before he had his blood clot. He was misdiagnosed. But he was lucky. The clot grew tight. One leg will always be thicker than the other one but he was not harmed.

    Liked by 1 person

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s