General Health

Venous thromboembolism

Suspected deep vein thrombosis is stratified by pre-test probability before D-dimer or ultrasound, because a negative D-dimer only excludes DVT in patients who are already unlikely to have it.

What you are actually deciding

The score is a pre-test probability, not a diagnosis. It performs less well in hospital inpatients and in patients with previous DVT, both common in post-operative orthopaedic practice, so lower the threshold for imaging in those groups. Before surgery the question changes from probability to risk: the Caprini model adds up recorded risk factors so that a hospital protocol can assign prophylaxis, and it says nothing about whether a clot is already there.

Clinical calculator1

Caprini Calculator37 items
Caprini Risk Assessment Model for venous thromboembolismThe Caprini Risk Assessment Model estimates the risk of venous thromboembolism in a surgical patient by adding risk factors weighted 1, 2, 3 or 5 points — with elective lower limb arthroplasty, a hip, pelvis or leg fracture, stroke and acute spinal cord injury each worth 5 — to give a total that hospital protocols then map to a prophylaxis level.

Clinical decision rule1

Wells DVT Rules10 items
Wells Score for Deep Vein ThrombosisThe Wells score for deep vein thrombosis estimates pre-test probability from ten clinical criteria, nine of which add a point and one of which subtracts two, stratifying patients into low, moderate and high probability groups that carry roughly 5%, 17% and 53% prevalence of DVT.

Clinical calculator1

Clinical decision rule1

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