Which clinical rule estimates pretest probability for pulmonary embolism and guides imaging?

• A. APGAR score
• B. CURB-65
• C. SOFA score
• D. Wells score (or revised Geneva score)

Answer: (D)

Estimating pretest probability for pulmonary embolism using a clinical decision rule helps decide who needs imaging and who can be spared unnecessary tests. The Wells score does exactly this by combining simple clinical features to categorize a patient’s probability of PE and then guide the next step in testing (often a D-dimer if probability is low, or direct imaging if probability is high). It includes factors like signs of DVT, whether PE is the more likely diagnosis, elevated heart rate, recent immobilization or surgery, prior DVT/PE, hemoptysis, and malignancy. A higher Wells score points toward a higher pretest probability, making imaging such as CT pulmonary angiography more likely to be pursued promptly.

Other scores mentioned serve different purposes. An APGAR score evaluates newborn vitality, CURB-65 assesses pneumonia severity, and the SOFA score tracks organ failure in critically ill patients. These do not estimate the pretest probability of PE or guide PE-specific imaging decisions.