To improve diagnosis of pulmonary embolism (PE), the authors constructed a simple scoring system to estimate the probability
of PE. Clinical predictors included age, previous venous thromboembolism, recent surgery or fracture, active cancer, unilateral
lower-limb pain, hemoptysis, heart rate, a tender deep vein, and unilateral leg edema. In the validation set, the prevalence
of PE was 8%, 29%, and 74% in the low-, intermediate-, and high-probability categories, respectively.