Methodology Score: 4/5
Usefulness Score: 4.5/5
This prospective multicenter European prospective cohort study found that using age-adjusted D-Dimer cut off (age x10) in conjunction with the Wells or Geneva clinical decision rules increased the utility of the d-dimer to rule-out PE with an associated 11% absolute decrease in the unnecessary imaging. JC attendees agreed that this study is the first to address this question prospectively and if supported by robust future North American studies may lead to change in our current practice patterns.
By: Dr. Elena Poliakova
(Presented June 2014)
Prospective cohort studies are vulnerable to selection bias (the patients selected for the study population may have been systematically different than the population of interest). One way to mitigate against this bias is to consecutively enroll patients as they arrive for clinical care. This challenging approach, when done well, mitigates selection bias in otherwise convenience sampling. By: Dr. Lisa Calder