Hong Kong Respiratory Medicine

Renée A. Douma, MD; Inge C.M. Mos, MD; Petra M.G. Erkens, MSc; Tessa A.C. Nizet, MD; Marc F. Durian, MD; Marcel M. Hovens, MD; Anja A. van Houten, MD; Herman M.A. Hofstee, MD; Frederikus A. Klok, MD; Hugo ten Cate, MD; Erik F. Ullmann, MD; Harry R. Büller, MD; Pieter W. Kamphuisen, MD; and Menno V. Huisman, MD,for the Prometheus Study Group. Annals of Internal Medicine 2011, 154: 709-718
Background:
Several clinical decision rules (CDRs) are available to exclude acute pulmonary embolism (PE), but they have not been directly compared.
Objective:
To directly compare the performance of 4 CDRs (Wells rule, revised Geneva score, simplified Wells rule, and simplified revised Geneva score) in combination with d-dimer testing to exclude PE.

Design:
Prospective cohort study.

Setting:
7 hospitals in the Netherlands.

Patients:
807 consecutive patients with suspected acute PE.

Intervention:
The clinical probability of PE was assessed by using a computer program that calculated all CDRs and indicated the next diagnostic step. Results of the CDRs and d-dimer tests guided clinical care.

Measurements:
Results of the CDRs were compared with the prevalence of PE identified by computed tomography or venous thromboembolism at 3-month follow-up.

Results:
Prevalence of PE was 23%. The proportion of patients categorized as PE-unlikely ranged from 62% (simplified Wells rule) to 72% (Wells rule). Combined with a normal d-dimer result, the CDRs excluded PE in 22% to 24% of patients. The total failure rates of the CDR and d-dimer combinations were similar (1 failure, 0.5% to 0.6% [upper-limit 95% CI, 2.9% to 3.1%]). Even though 30% of patients had discordant CDR outcomes, PE was not detected in any patient with discordant CDRs and a normal d-dimer result.

Limitation:
Management was based on a combination of decision rules and d-dimer testing rather than only 1 CDR combined with d-dimer testing.

Conclusion:
All 4 CDRs show similar performance for exclusion of acute PE in combination with a normal d-dimer result. This prospective validation indicates that the simplified scores may be used in clinical practice.

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