Performance of 4 clinical decision rules in the diagnostic management of acute pulmonary embolism: a prospective cohort study.

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.

PRIMARY FUNDING SOURCE

Academic Medical Center, VU University Medical Center, Rijnstate Hospital, Leiden University Medical Center, Maastricht University Medical Center, Erasmus Medical Center, and Maasstad Hospital.