Diagnosing pulmonary embolism: Running after the decreasing prevalence of cases among suspected patients

Abstract

In summary, as long as the proportion of PE was about 20% among suspected patients, a 99% sensitive and 40% specific D-dimer test allowed excluding PE in about one third of suspected outpatients. It was effective for selecting patients who should proceed to further imaging procedures and one out of three patients with a positive D-dimer had a PE. The progressive decrease in the proportion of confirmed cases among suspected patients, especially in North America, has resulted in an important cost-efficacy unbalance in the diagnostic strategies based on D-dimer testing, as the proportion of patients with positive D-dimer but without PE increases dramatically. Attempts should be made to resolve this issue, e.g. by increasing the specificity of the test or by better selecting patients requiring investigation for PE, with the constraint to maintain a high sensitivity of the initial test. Indeed, even if PE is a life-threatening disease, and wishing to rule it out is a laudable intention, we may quation whether implementing a costly diagnostic work-up in a population with an only 5% prevalence of the disease is still reasonable. Hence, the question may be no more how should we investigate PE but rather in whom? © 2004 International Society on Thrombosis and Haemostasis.