Competing prediction rules for DVT

Safely ruling out deep venous thrombosis in primary care. Ann Intern Med 150 (4):229-35. PMID: 19221374

The history of clinical prediction rules for DVT:

1. The original Wells prediction rule was published in 1995 with 12 predictor variables (PMID: 7752753).
2. Wells modified his rule in 1997 to use only 9 variables (PMID: 9428249).
3. In 2003, Wells revised a 10 point rule that adds a point for history of previous DVT (PMID: 14507948.
4. In 2005, a study in the Annals of Internal Medicine was titled "Wells Rule Does Not Adequately Rule Out Deep Venous Thrombosis in Primary Care Patients." However, this study was started in 2002 and so studied the 1997 version of the Wells rule (PMID: 16027451).
5. Now the authors of the 2005 study have published the performance of their own rule (PMID: 19221374), named the AMUSE rule for "Amsterdam Maastricht Utrecht Study on thromboEmbolism."

We are left with the 2003 Wells rule and the AMUSE rule without a direct comparison. An insightful editorial accompanying the current publication by AMUSE notes that the two rules have similar negative likelihood ratios - actually the Wells rule has a slightly better LR- and has been externally validated.

Regarding the physical examination, both rules include the following findings:

• Distended, non-varicose collateral veins
• Calf circumference discrepancy greater than 3 cm measured 10 cm below the tibial tuberosity

The Wells rule also includes:

• Pitting edema (confined to symptomatic leg)
• Swelling of entire leg
• Localized pain along distribution of deep venous system

In addition to the physical findings, the Wells rule includes the sometimes subjective finding, "Alternative diagnosis at least as likely."

In summary, I appreciate the AMUSE group's efforts at creating a less subjective prediction rule for DVT and look forward to a direct comparison of the current versions of both rules. Until then, I will stay with the Wells rule.

This has been added to http://en.citizendium.org/wiki/Deep_venous_thrombosis.

Citation:

Büller HR, Ten Cate-Hoek AJ, Hoes AW, Joore MA, Moons KG, Oudega R, Prins MH, Stoffers HE, Toll DB, van der Velde EF, van Weert HC, & AMUSE (Amsterdam Maastricht Utrecht Study on thromboEmbolism) Investigators (2009). Safely ruling out deep venous thrombosis in primary care. Annals of internal medicine, 150 (4), 229-35 PMID: 19221374