Modified Wells Score for Pulmonary Embolism (PE)

Cautions

• For patients with suspected pulmonary embolism. The original paper (Wells 2000) splits the score in two ways: 3 levels (less than 2 points, 2 to 6 points, more than 6 points) and 2 levels (4 points or fewer is "PE unlikely", more than 4 is "PE likely"). The screen shows both
• "An alternative diagnosis is less likely than pulmonary embolism" is the item worth 3 points, and it rests on the judgment of the examining clinician
• In the derivation study of the original paper, 7.8% of the patients with 4 points or fewer had PE. The figures for excluding PE together with D-dimer apply to the test the original paper used, SimpliRED
• Immobilization counts when it lasts more than 3 days, as in Table 1 of van Belle 2006 (">3 d"), so exactly 3 days scores 0. One review (F1000Research 2020, Table 3a) writes "at least 3 days", so sources differ on exactly 3 days. The abstract of the original paper gives no number of days; it speaks of immobilization or surgery within 4 weeks
• The van Belle study (JAMA 2006) used the 2-level rule. Of 1028 patients classed as "PE unlikely", with a normal D-dimer and no anticoagulant treatment, 5 (0.5%) had VTE within 3 months. That figure comes from a study population that excluded, among others, patients who were pregnant, hemodynamically unstable, had a life expectancy of less than 3 months, had renal insufficiency (creatinine clearance below 30 mL/min), were under 18 years of age or were allergic to contrast agents; the study gives no results for such patients
• The points for a previous DVT or pulmonary embolism are 1.5 in the abstract of the original paper and in a review (Semin Thromb Hemost 2024). Another review (F1000Research 2020) gives 1 point, but the points of the original paper were followed