Are all pulmonary embolism clinical decision rules equal?

Clinical Question: Are four common clinical decision rules, in combination with normal D-dimer results, comparable in their ability to clinically exclude the diagnosis of pulmonary embolism?
Article Chosen: Douma RA, Mos ICM, Erkens PMG, et al. Performance of 4 clinical decision rules in the diagnostic management of acute pulmonary embolism: a prospective cohort study. Ann Intern Med 2011;154:709-18.
Objective: To directly compare the performance of four different clinical decision rules, the Wells rule, revised Geneva score, simplified Wells rule, and simplified revised Geneva score, in combination with D-dimer results, to exclude pulmonary embolism.