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307 pages added, reviewed or updated during the last month (last updated: 27/11/2020)

307 pages added, reviewed or updated during the last month (last updated: 27/11/2020)

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Wells prediction score for deep vein thrombosis (DVT)

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The clinical diagnosis of DVT is generally thought to be unreliable. However, Wells et al. suggest a well-validated clinical prediction rule which could be used to estimate the pretest probability.

  • the original version classified patients into low, moderate or high risk, based on the presence or absence of clinical criteria
  • in the revised Wells scoring system, the risk categories were trimmed to “unlikely” or “likely” (1,2).

The revised Wells score or criteria for assessment of suspected DVT is mentioned below (with a possible score of -2 to 9):



active cancer (treatment within last six months or palliative)


calf swelling ≥3 cm compared to asymptomatic calf (measured 10 cm below tibial tuberosity)  


collateral superficial veins (non-varicose) 


pitting oedema (confined to symptomatic leg) 


swelling of entire leg


localised tenderness along distribution of deep venous system 


paralysis, paresis, or recent cast immobilisation of lower extremities


recently bedridden ≥3 days, or major surgery requiring regional or general anesthetic in the previous 12 weeks 


previously documented deep-vein thrombosis 


alternative diagnosis at least as likely as DVT


Clinical probability simplified score 

  • DVT “likely” - 2 points or more
  • DVT is “unlikely” - 1 point or less (3)

The sensitivity for DVT of the Wells criteria is between 77–98% while the specificity is 38–58%. Therefore, it cannot be as the sole diagnostic modality for DVT (2)


Last edited 04/2018