Clinical Calculators

Wells Score for Deep Vein Thrombosis (DVT)

Pretest probability score for patients with suspected deep vein thrombosis of the leg

10 items left

Active cancer (receiving treatment within the previous 6 months, or currently receiving palliative treatment)
Paralysis or paresis of a leg, or a leg recently immobilized in a cast
Recently bedridden for 3 days or more, or had a major operation

Sources differ on the number of days and on the period for major surgery (see the cautions below)

Localized tenderness along the deep venous system
Entire leg swollen
The calf is 3 cm or more larger than on the asymptomatic side (measured 10 cm below the tibial tuberosity)
Pitting edema in the symptomatic leg only
Visible collateral superficial veins that are not varicose veins
Previously documented DVT
An alternative diagnosis is at least as likely as DVT

Cautions

  • For outpatients with suspected DVT of the leg. The original paper (2003) concluded that when DVT is unlikely and the D-dimer is negative, DVT can be excluded without an ultrasound examination
  • The "previous DVT" item scores only in the modified rule (footnote of Table 1 in BMJ 2014). Some sources print a table of 9 items without this item (Korean Practice Guidelines 2016)
  • The number of bedridden days is written differently: more than 3 days in BMJ 2014, 3 days in J Blood Med 2011, and 3 days or more in World J Emerg Surg 2016. The period for major surgery also differs: within 4 weeks (BMJ 2014), or within 12 weeks and needing general or regional anesthesia (J Blood Med 2011)
  • For the calf, sources differ between "3 cm or more" and "more than 3 cm"

References

  1. Wells PS, Anderson DR, Rodger M, Forgie M, Kearon C, Dreyer J, Kovacs G, Mitchell M, Lewandowski B, Kovacs MJ. Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis. N Engl J Med. 2003;349(13):1227-1235. (Abstract) (original not seen) PMID: 14507948, DOI: 10.1056/NEJMoa023153[Original article]
  2. Wells PS, Anderson DR, Bormanis J, Guy F, Mitchell M, Gray L, Clement C, Robinson KS, Lewandowski B. Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet. 1997;350(9094):1795-1798. (Abstract) (original not seen) PMID: 9428249, DOI: 10.1016/S0140-6736(97)08140-3[Original article]
  3. Wells PS, Owen C, Doucette S, Fergusson D, Tran H. Does this patient have deep vein thrombosis? JAMA. 2006;295(2):199-207. (Abstract) PMID: 16403932, DOI: 10.1001/jama.295.2.199[Review article]
  4. Geersing GJ, Zuithoff NP, Kearon C, et al. Exclusion of deep vein thrombosis using the Wells rule in clinically important subgroups: individual patient data meta-analysis. BMJ. 2014;348:g1340. (Table 1) PMID: 24615063, DOI: 10.1136/bmj.g1340, https://pmc.ncbi.nlm.nih.gov/articles/PMC3948465/[Review article]
  5. Kesieme E, Kesieme C, Jebbin N, Irekpita E, Dongo A. Deep vein thrombosis: a clinical review. J Blood Med. 2011;2:59-69. (Table 1) PMID: 22287864, DOI: 10.2147/JBM.S19009, https://pmc.ncbi.nlm.nih.gov/articles/PMC3262341/[Review article]
  6. Modi S, Deisler R, Gozel K, et al. Wells criteria for DVT is a reliable clinical tool to assess the risk of deep venous thrombosis in trauma patients. World J Emerg Surg. 2016;11:24. (Table 1) PMID: 27279896, DOI: 10.1186/s13017-016-0078-1, https://pmc.ncbi.nlm.nih.gov/articles/PMC4898382/[Review article]
  7. Min SK, Kim YH, Joh JH, et al. Diagnosis and treatment of lower extremity deep vein thrombosis: Korean practice guidelines. Vasc Specialist Int. 2016;32(3):77-104. (Table 3) PMID: 27699156, DOI: 10.5758/vsi.2016.32.3.77, https://pmc.ncbi.nlm.nih.gov/articles/PMC5045251/[Guideline]

Checked on: 2026-10-13

Disclaimer

This calculation is intended to support the judgment of healthcare professionals. Results are for reference only; decisions about diagnosis and treatment must be made by the responsible healthcare professional. The values you enter never leave your device.