Confirmation of asthma diagnosis in the community.

of the Geneva model. As for the Wells score used in our study, we think that neither dichotomised nor trichotomised scores make too much sense if they are combined with a D-dimer test. It must be noted that positive D-dimer test allows the shifting of some patients from the ‘‘unlikely’’ PE arm of the dichotomised Wells score back to the ‘‘likely’’ arm. Since only few COPD studies related to the Wells scoring system exist in the literature, we preferred including all COPD patients for evaluation who are considered naturally at risk for PE, as mentioned above, to excluding some unlikely PE patients with negative D-dimer test results. We believe this approach would be necessary for the further validation of the Wells system in this specific group of patients.