TABLE
Wells score estimates probability of deep vein thrombosis
The elements of the Wells score should be ascertained in the usual evaluation of a patient with suspected DVT.
| 1 POINT EACH FOR: | |
| Active cancer | |
| Paralysis, paresis, recent plaster immobilization of lower limb | |
| Recently bedridden for >3 days or major surgery in past 4 weeks | |
| Localized tenderness along distribution of deep venous system | |
| Entire leg swollen | |
| Calf swelling >3 cm compared to asymptomatic leg | |
| Pitting edema | |
| Collateral superficial veins | |
| –2 POINTS FOR: | |
| Alternative diagnosis as likely or more likely than that of DV T | |
| PROBABILITY: | |
| High | >3 points |
| Intermediate | 1 or 2 points |
| Low | <0 points |
What’s New?: This evidence is definitive
This PURL may be old news to you if you have been watching the evolution of DVT risk scoring and the role of D-dimer. This is one of those approaches for which the evidence grows over time and the adoption spreads slowly. We felt that the cumulative evidence, especially this decision analysis,1 clearly points to the most current Wells score and the D-dimer as the approach of choice for initial evaluation of suspected DVT. This more definitive evidence and the variability of practice both reported in the literature and described by our clinician reviewers led us to decide that this study is a priority update and a practice changer—even if it is a slow practice changer.
Caveats: One strategy doesn’t fit all
The authors stress that their results are most applicable to outpatients with a suspected first DVT.1
- D-dimer levels can be elevated in pregnancy, myocardial infarction, cancer, trauma, and postsurgery. These recommendations do not apply to patients with any of these conditions, patients on anticoagulation therapy, intravenous drug abusers, or patients with recurrent DVT.
- In practices where D-dimer testing is not feasible, ultrasound remains an effective approach to suspected DVT.
Challenges To Implementation: Haven’t memorized the Wells score? No problem
As simple as it seems to add up the Wells score, most of us are not likely to recall the scoring system unless we use it often enough to have memorized it. Lack of immediate access to scoring systems in the context of a hectic schedule is a barrier to adoption.
Fortunately, many handheld and Web-based electronic knowledge resources are available for easy retrieval of the Wells DVT score. Some will even dynamically calculate the score for you.
Ideally, scoring systems such as this need to be integrated into electronic health records for easy access at the point of patient care.
Which Wells score?
There are several other scoring systems for estimating DVT risk, but the Wells DVT score is the best studied. To add to the confusion, Wells and his colleagues have made continuous improvements over time, such that there are several versions of the Wells DVT score.
In a quick Google search, we found six versions in which either the criteria or the interpretation was different, not to mention multiple other systems. The one used in this meta-analysis1 and described in this PURL is the most recent, most accurate and best studied.
PURLs methodology
This study was selected and evaluated using the Family Physician Inquiries Network’s Priority Updates from the Research Literature Surveillance System (PURLs) methodology.