Emergency and critical care
Wells score (DVT and PE)
The Wells score turns clinical findings into a pretest probability of deep vein thrombosis or pulmonary embolism, which is what decides whether a D-dimer or imaging comes next. Pick the version you need, because the two have different items and different weights.
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This calculator is provided for reference and education. It does not replace clinical assessment, examination, current guidelines, local protocol, or professional judgment. Verify every result before acting on it. Nirogix accepts no liability for clinical decisions made using this tool.
The formula
- DVT: nine criteria at 1 point each, minus 2 if an alternative diagnosis is at least as likely. Range −2 to 9.
- PE: clinical signs of DVT 3; PE most likely 3; tachycardia 1.5; immobilization or surgery 1.5; prior VTE 1.5; hemoptysis 1; malignancy 1. Range 0 to 12.5.
Worked example
PE version: signs of DVT (3) plus tachycardia (1.5) plus prior PE (1.5) = 6, moderate probability
When to use it
- Deciding whether a D-dimer will be informative
- Structuring the decision between discharge, D-dimer and imaging
And when not to
- A score is a pretest probability, not a diagnosis. It changes what test comes next; it does not replace one.
- D-dimer is unhelpful in a high-probability patient, in pregnancy, and often in the elderly and in malignancy.
- The DVT and PE versions are different instruments. Do not mix items between them.
References
- Value of assessment of pretest probability of deep-vein thrombosis — Wells PS et al., The Lancet, 1997
- Derivation of a simple clinical model to categorize patients probability of pulmonary embolism — Wells PS et al., Thrombosis and Haemostasis, 2000
Last reviewed 07/09/2026.
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These calculators are free and always will be. We also build Nirogix, a hospital management system for Indian clinics and hospitals. The same calculations are planned inside the consultation record, pre-filled from the chart.