DVT Clinical Probability (Well's)

Determine pretest probability of DVT to guide workup

The global unit selector only affects unanswered questions
1.Cancer treatment within last 6 months OR current palliation?
2.Paralysis OR Paresis OR Cast of lower extremity?
3.Bedridden for at least 3 days in last 4 weeks OR Major surgery in last 12 weeks?
4.Tenderness localized along deep venous system?
5.Swelling of entire leg?
6.Unilateral calf swelling >3cm compared to other side?
7.Unilateral pitting edema?
8.Superficial collateral veins?
9.Prior DVT?
10.Alternative diagnosis as or more likely than DVT?
Created by

1. Cancer treatment within last 6 months OR current palliation?

Created by
0/10 completed

About this Calculator

The diagnostic accuracy for DVT improves when the clinical probability is estimated before the use diagnostic tests. It is important to note that, when using the scoring system by itself, DVT cannot be ruled out completely in patients with a low probability score or confirmed in patients with a high probability score. However, use of such a score can help inform interpretation of subsequent diagnostic tests and reduce the need for invasive testing. For instance, patients with low clinical probability on the Wells predictive rule have a prevalence of DVT of less than 5%. In some studies, the combination of a low clinical probability and a negative d-dimer result can exclude DVT without ultrasound or further testing. Because multiple D-dimer assays are available, physicians should ensure that a proven high-sensitivity assay is available and that the test has been validated/audited in their institution.


Wells PS, Anderson DR, Bormanis J, Guy F, Mitchell M, Gray L, Clement C, Robinson KS, Lewandowski B.

Value of assessment of pretest probability of deep-vein thrombosis in clinical management.

Lancet 1997 December 20, 350 (9094): 1795-8

Wells PS, Anderson DR, Rodger M, Forgie M, Kearon C, Dreyer J, et al.

Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis.

N Engl J Med. 2003;349:1227-35.

Legal Notices and Disclaimer

© 2020 QxMD Software Inc., all rights reserved. No part of this service may be reproduced in any way without express written consent of QxMD. This information should not be used for the diagnosis or treatment of any health problem or disease. This information is not intended to replace clinical judgment or guide individual patient care in any manner. Click here for full notice and disclaimer.