Wells' Criteria for DVT
Calculates risk of DVT
Treatment or palliation within 6 months
Measured 10 cm below tibial tuberosity
Reference
Summary
The Wells' Criteria for DVT can assist providers in identifying patients who are overall unlikely (low risk) to have a DVT. Further testing with d-dimer can safely rule our DVT without the need for an ultrasound. This tool is intended for the outpatient and emergency department setting, and only for patients who are considered at risk for DVT. The criteria is considered less useful in the hospital setting (Silveira, 2015). Depending on the research study, there are a few versions of the criteria with minor differences. The criteria set in this tool is the most widely validated (Wells, 2003).
.Summary
Depending on the research study, there are a few versions of the criteria with minor differences. The criteria set in this tool is the most widely validated (Wells, 2003).
- High suspicion for DVT should warrant imaging regardless of Wells score.
- If pulmonary embolism (PE) is on the differential, consider additional decision aids, such as the Wells PE or PERC rule.
The formula consists of the sum of the selected points. Clinical gestalt is an important part of the score ("Alternative diagnosis to DVT as likely or more likely"). A "Yes" is given "-2" points.
| Variable | Points |
| Active Cancer | No (0) or Yes (1) |
| Bedridden recently > 3 days or major surgery within 12 weeks | No (0) or Yes (1) |
| Calf swelling > 3 cm compared to the other leg | No (0) or Yes (1) |
| Collateral (nonvaricose) superficial veins present | No (0) or Yes (1) |
| Entire leg swollen | No (0) or Yes (1) |
| Localized tenderness along the deep venous system | No (0) or Yes (1) |
| Pitting edema, confined to symptomatic leg | No (0) or Yes (1) |
| Paralysis, paresis or recent plaster immobilization of the lower extremity | No (0) or Yes (1) |
| Previously documented DVT | No (0) or Yes (1) |
| Alternative diagnosis to DVT as likely or more likely | No (0) or Yes (-2) |
Results
"Unlikely" (score ≤ 0): Low risk for DVT (5% prevalence).
Management: Proceed to d-dimer testing
- If negative (high or moderate sensitivity d-dimer), no further imaging is required (probability of DVT is <1%).
- If positive, proceed to US testing.
- A negative US is sufficient for DVT rule out.
- A positive US is concerning for DVT. Strongly consider anticoagulation treatment.
Moderate risk for DVT (Score 1-2). A score of 1-2 has a pretest DVT probability of 17%.
Management: Proceed to high-sensitivity d-dimer* testing
- If negative (high sensitivity d-dimer), no further imaging is required (probability of DVT is <1%).
- If positive, proceed to ultrasound testing.
- A negative ultrasound is sufficient for DVT rule out.
- A positive ultrasound is concerning for DVT. Strongly consider anticoagulation treatment.
*Moderate sensitivity d-dimer is not sufficient in this risk group to rule out without ultrasound.
"Likely" (score ≥ 3): High risk for DVT. A score of ≥ 3 has a pretest DVT probability of 17-53%.
Management:
- All high-risk patients for DVT ("Likely") should receive ultrasound (US).
- Obtain D-dimer to further risk-stratify
- If negative (d-dimer),
- A negative US is sufficient for ruling out DVT, consider discharge.
- A positive US is concerning for DVT, consider anticoagulation treatment.
- If positive (d-dimer),
- A negative US is concerning for DVT. Consider repeat US within 1 week for re-evaluation.
- A positive US is concerning for DVT. Strongly consider anticoagulation treatment.
- If negative (d-dimer),
.
Instructions
Intended only for patients who are considered at risk for DVT.
- Less useful in hospitalized patients (Silveira, 2015).
- Clinical gestalt is an important part of the score ("Alternative diagnosis to DVT as likely or more likely"). A "Yes" is given "-2" points.
Literature
- Accuracy of clinical assessment of deep-vein thrombosis. Lancet. 1995 May 27;345(8961):1326-30. — Wells PS, Hirsh J, Anderson DR, Lensing AW, Foster G, Kearon C, Weitz J, D'Ovidio R, Cogo A, Prandoni P.
- Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet. 1997 December 20; 350(9094): 1795-1978. — Wells PS, Anderson DR, Bormanis J, Guy F, Mitchell M, Gray L.
- Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis. N Engl J Med. 2003 Sep 25;349(13):1227-35. — Wells PS, Anderson DR, Rodger M, Forgie M, Kearon C, Dreyer J, Kovacs G, Mitchell M, Lewandowski B, Kovacs MJ.
- Diagnosis and treatment of deep-vein thrombosis. CMAJ. 2006 Oct 24;175(9):1087-92. — Scarvelis D, Wells PS.
- Performance of Wells Score for Deep Vein Thrombosis in the Inpatient Setting. JAMA Intern Med. 2015 Jul;175(7):1112-7. — Silveira PC, Ip IK, Goldhaber SZ, Piazza G, Benson CB, Khorasani R.
- Jennifer Glen , DNP, FNP-BC — EVAL Health, Chief Medical Officer