Wells Score for PE Calculator

Philip Wells and colleagues derived the score in patients evaluated for pulmonary embolism and published the original model in 1998. It includes a clinician judgment item and belongs inside a validated diagnostic pathway with examination, assay-specific D-dimer interpretation, and imaging decisions. It is not designed for self-triage. If you may have symptoms of pulmonary embolism, seek urgent medical assessment instead of relying on this score.

The three-tier interpretation labels scores below 2 as low, 2 to 6 as moderate, and above 6 as high pretest probability. The dichotomized version labels 4 or less as PE unlikely and above 4 as PE likely. These categories are not standalone probabilities for an individual. A clinician must apply the version validated for the local diagnostic pathway and patient population.

PERC is a separate rule that clinicians may use only after judging a patient to have a very low pretest probability of pulmonary embolism. A negative PERC result does not make it safe for a person to rule out PE at home, and a positive item does not diagnose PE. The appropriate pathway depends on age, pregnancy, clinical setting, local assays, and current guidelines.

A high-sensitivity D-dimer can help exclude PE when a validated clinical pathway first establishes an appropriate low or intermediate pretest probability. The result depends on the assay, units, age adjustment, and pathway used. A positive D-dimer is nonspecific, while a negative result is not sufficient in every high-risk presentation. Interpretation belongs to the treating clinician.

A clinician selects imaging after considering pretest probability, D-dimer results when appropriate, hemodynamic stability, pregnancy, kidney function, contrast risk, and local resources. A Wells score alone does not order or rule out CTPA. Suspected PE with chest pain, unexplained shortness of breath, fainting, coughing blood, or instability needs urgent medical evaluation.