Kearon C, de Wit K, Parpia S, et al. - In this prospective study in which pulmonary embolism was recognized to be ruled out without further testing in outpatients with a low clinical pretest probability (C-PTP) and a d-dimer level of less than 1000 ng per milliliter or with a moderate C-PTP and a d-dimer level of less than 500 ng per milliliter, experts determined the diagnosis of pulmonary embolism with d-dimer adjusted to clinical probability. A total of 2,017 individuals were recruited and assessed. Results imply that for pulmonary embolism during follow-up, a combination of a low C-PTP and a d-dimer level of less than 1000 ng per milliliter recognized a group of people at low risk.