Wells Score: Pulmonary Embolism (PE) Probability
Online Wells Score calculator to evaluate the clinical probability of Pulmonary Embolism (PE). Validated 2-tier model by ESC guidelines (D-dimer vs Imaging).
Interpretation & Recommendations (ESC)
The Wells score stratifies the clinical probability of pulmonary embolism to guide further diagnostic testing.
What is the Wells Score for PE?
The Wells Score for Pulmonary Embolism (PE) is a validated clinical prediction rule. It helps emergency physicians and pulmonologists assess the pre-test probability of a pulmonary embolism before ordering costly or radiating tests (like a CT pulmonary angiogram).
2-Tier Model (Recommended)
According to the latest European Society of Cardiology (ESC) guidelines, the dichotomous (2-tier) model is preferred in emergency clinical practice. It separates patients into two groups: "PE Unlikely" (where D-dimers are indicated) and "PE Likely" (requiring immediate imaging).
Age-Adjusted D-dimer Cutoff
For patients > 50 years old with an "Unlikely" score, apply the age-adjusted formula:
- D-dimer cutoff = Age × 10 µg/L
- Example: For a 75-year-old patient, the positivity threshold is 750 µg/L (instead of 500).
Clinical Probability
| Wells Score | Clinical Probability | Recommended Action |
|---|---|---|
| 0 - 4 | PE Unlikely | D-dimer testing |
| > 4 | PE Likely | CT pulmonary angiogram (CTPA) |
References:
1. Wells PS, et al. Derivation of a simple clinical model to categorize patients probability of pulmonary embolism. Thromb Haemost. 2000.
[NIH - PubMed]
2. Konstantinides SV, et al. (ESC Guidelines). 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism. Eur Heart J. 2020.
[ESC Guidelines]
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