Wells' Criteria for DVT

Wells Criteria for DVT

Active Cancer (treatment within 6 months or palliative)

Bedridden >3 days or major surgery within 12 weeks

Calf swelling >3 cm compared to other leg

Collateral superficial veins (non-varicose)

Entire leg swollen

Localized tenderness along deep venous system

Pitting edema confined to symptomatic leg

Paralysis, paresis, or recent cast immobilization

Previously documented DVT

Alternative diagnosis at least as likely as DVT

Wells' DVT Score: 0

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Calculates risk of DVT based on clinical criteria.

Why Use

Traditional testing for DVT involved multiple lower extremity US which are associated with time and cost. Utilization of the Wells’ DVT criteria can determine those patients who are overall unlikely to have a DVT. Further testing with d-dimer can safely rule out DVT without the need for US.

When to Use

The Wells’ DVT Criteria can be used in the outpatient and emergency department setting. By risk stratifying to low risk (Wells’ Score <2) and a negative d-dimer the clinician can exclude the need for ultrasound (US) to rule out DVT.

Formula

Addition of the selected points: Variable Points Active cancer (treatment or palliation within 6 months) No 0 Yes 1 Bedridden recently >3 days or major surgery within 12 weeks No 0 Yes 1 Calf swelling >3 cm compared to the other leg (measured 10 cm below tibial tuberosity) No 1 Yes 1 Collateral (nonvaricose) superficial veins present No 0 Yes 1 Entire leg swollen No 0 Yes 1 Localized tenderness along the deep venous system No 0 Yes 1 Pitting edema, confined to symptomatic leg No 0 Yes 1 Paralysis, paresis, or recent plaster immobilization of the lower extremity No 0 Yes 1 Previously documented DVT No 0 Yes 1 Alternative diagnosis to DVT as likely or more likely No 0 Yes -2 Note: there are a few versions of the criteria with minor differences based on the study; this set is the most widely validated, based on Wells 2003 .

Pearls / Pitfalls

The Wells’ Criteria for Deep Vein Thrombosis (DVT) are used to stratify patients by their risk of DVT. There is an overall low prevalence of DVT in cases with low (<25%) clinical suspicion patients. The Wells score inherently incorporates clinical gestalt with a minus 2 score for alternative diagnosis more likely. Sequelae from DVT include pulmonary embolism (PE) and pulmonary hypertension, which have an associated mortality of 1-8%. Anticoagulation is the mainstay treatment for DVT with its own associated risks of bleeding.

Management

Patients can be divided into “DVT unlikely” and “DVT likely” groups based on Wells score. An additional moderate risk group can be added based on the sensitivity of the d-dimer being used. A score of 0 or lower is associated with DVT unlikely with a prevalence of DVT of 5%. These patients should proceed to d-dimer testing: A negative high or moderate sensitivity d-dimer results in a probability <1 % and no further imaging is required. A positive d-dimer should proceed to US testing. A negative US is sufficient for DVT rule out. A positive US is concerning for DVT; strongly consider treatment with anticoagulation. A score of 1-2 is considered moderate risk with a pretest probability of 17%.* These patients should proceed to high-sensitivity d-dimer testing (moderate sensitivity d-dimer is not sufficient). A negative high-sensitivity d-dimer is sufficient for rule out of DVT in a moderate risk patient with a probability of <1%. A positive high sensitivity d-dimer should proceed to US testing. A negative US is sufficient for ruling out DVT. A positive US is concerning for DVT, strongly consider treatment with anticoagulation. A score of 3 or higher suggests DVT is likely. Pretest probability 17-53%. All DVT likely patients should receive US. D-dimer testing should be utilized to help risk-stratify these DVT-likely patients. In DVT likely patients with negative d-dimer: A negative US is sufficient for ruling out DVT, consider discharge. A positive US should be concerning for DVT, strongly consider treatment with anticoagulation. In DVT likely patients with a positive d-dimer: A positive US should be concerning for DVT, strongly consider treatment with anticoagulation. A negative US is still concerning for DVT. A repeat US should be performed within 1 week for re-evaluation. *Group should only undergo d-dimer testing for rule out without ultrasonography if a high-sensitivity d-dimer is being used.

Critical Actions

No decision rule should trump clinical gestalt. High suspicion for DVT should warrant imaging regardless of Wells score. The Wells’ Criteria for DVT is utilized for the workup of DVT. The presence of DVT is critical to the evaluation of possible PE, and if PE is on the differential, alternative decision aids such as the Wells’ PE or PERC Rule should be entertained.

Advice

As with all clinical decision aids, the Wells’ DVT criteria is meant to aid clinical decision making and not force management. The Wells’ DVT criteria should only be applied after a detailed history and physical is performed. The Wells’ DVT criteria should only be applied to those patients who have been deemed at risk for DVT. If there is no concern for DVT, then there is no need for risk stratification.

More Information

Interpretation: Wells' Score Risk group Prevalence of DVT ≤0 Low/unlikely 5% 1-2 Moderate 17% ≥3 High/likely 17-53%