Calculates probability of Pulmonary Embolism
Total Score
Low risk (PE probability < 5%). Consider PERC rule or D-Dimer.
Disclaimer: The clinical scoring and algorithms on this platform are intended strictly for professional informational purposes. They do not constitute a definitive medical diagnosis, treatment, or clinical decision. The final judgment and responsibility lie with the treating physician.
Yasal Uyarı: Bu platformdaki klinik skorlamalar ve algoritmalar yalnızca sağlık profesyonellerini bilgilendirme amaçlıdır. Herhangi bir kesin tıbbi teşhis, tedavi veya klinik karar yerine geçemez. Nihai karar ve sorumluluk hastayı yatak başında değerlendiren hekime aittir.
The Wells Criteria for Pulmonary Embolism (PE) stratifies patients into risk categories (historically Low/Moderate/High, currently often simplified to PE Unlikely / PE Likely) to guide further diagnostic workup. It is a cornerstone algorithm that effectively pairs clinical gestalt with objective risk factors to prevent over-utilization of CT Pulmonary Angiography (CTPA).
The criterion 'Alternative diagnosis less likely than PE' carries the most weight (3 points) and is entirely subjective. This demands careful clinical assessment to actively rule out conditions like pneumonia, pneumothorax, or musculoskeletal pain before defaulting to a PE workup.
Wells PS, Anderson DR, Rodger M, et al. Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer. Thromb Haemost. 2000;83(3):416-420.
Disclaimer: The clinical scoring and algorithms on this platform are intended strictly for professional informational purposes. They do not constitute a definitive medical diagnosis, treatment, or clinical decision. The final judgment and responsibility lie with the treating physician.
Apply the Wells PE score to adult patients presenting to the ED with unexplained dyspnoea, pleuritic chest pain, tachycardia, or haemoptysis where PE is a diagnostic consideration. Low probability (0–1.5) → pair with PERC rule first: if all 8 PERC criteria are negative, PE is excluded without D-Dimer. If PERC positive, order D-Dimer; if negative, discharge; if positive, proceed to CT Pulmonary Angiography (CTPA). Moderate (2–6) → D-Dimer; if elevated, CTPA. High (> 6) → CTPA directly, without D-Dimer.
The 'alternative diagnosis less likely than PE' criterion (3 points) is the highest single-point item in the score and is intentionally subjective — it requires the physician to compare the probability of PE against all other plausible diagnoses. If you are considering PE enough to calculate this score, but the clinical picture also strongly suggests pneumonia, COPD exacerbation, or musculoskeletal chest pain, the alternative-diagnosis item should NOT be scored. Practising and teaching the explicit verbalization of 'my leading diagnosis is X vs. PE' before scoring this item significantly improves diagnostic calibration.
D-Dimer has a very high negative predictive value for PE but near-zero specificity — it is elevated in sepsis, malignancy, post-surgical patients, and during pregnancy. In these populations, an elevated D-Dimer result after a low or moderate Wells score does NOT confirm PE; it mandates CTPA to confirm or exclude. Similarly, D-Dimer is generally not useful in high Wells score patients (the pre-test probability is already high enough that a negative D-Dimer cannot sufficiently exclude PE) — always go directly to CTPA in Wells > 6.