Clinical question: Which clinical decision rule—Wells rule, simplified Wells rule, revised Geneva score, or simplified revised Geneva score—is the best for evaluating a patient with a possible acute pulmonary embolism?
Background: The use of standardized clinical decision rules to determine the probability of an acute pulmonary embolism (PE) has significantly improved the diagnostic evaluation of patients with suspected PE. Several clinical decision rules are available and widely used, but they have not been previously directly compared.
Study design: Prospective cohort.
Setting: Seven hospitals in the Netherlands.
Synopsis: A total of 807 patients with suspected first episode of acute PE had a sequential workup with clinical probability assessment and D-dimer testing. When PE was considered unlikely according to all four clinical decision rules and a normal D-dimer result, PE was excluded. In the remaining patients, a CT scan was used to confirm or exclude the diagnosis.
The prevalence of PE was 23%. Combined with a normal D-dimer, the decision rules excluded PE in 22% to 24% of patients. Thirty percent of patients had discordant decision rule outcomes, but PE was not detected by CT in any of these patients when combined with a normal D-dimer.
This study has practical limitations because management was based on a combination of four decision rules and D-dimer testing rather than only one rule and D-dimer testing, which is the more realistic clinical approach.
Bottom line: When used correctly and in conjunction with a D-dimer result, the Wells rule, simplified Wells rule, revised Geneva score, and simplified revised Geneva score all perform similarly in the exclusion of acute PE.
Citation: Douma RA, Mos IC, Erkens PM, et al. Performance of 4 clinical decision rules in the diagnostic management of acute pulmonary embolism: a prospective cohort study. Ann Intern Med. 2011;154:709-718.
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