Using an age-dependent D-dimer cut-off value increases the number of older patients in whom deep vein thrombosis can be safely excluded.

Abstract

BACKGROUND:

D-dimer testing to rule out deep vein thrombosis is less useful in older patients because of a lower specificity. An age-adjusted D-dimer cut-off value increased the proportion of older patients (>50 years) in whom pulmonary embolism could be excluded. We retrospectively validated the efficacy of this cut-off combined with clinical probability for the exclusion of deep vein thrombosis.

DESIGN AND METHODS:

Five management study cohorts of 2818 consecutive outpatients with suspected deep vein thrombosis were used. Patients with non-high or unlikely probability of deep vein thrombosis were included in the analysis; four different D-dimer tests were used. The proportion of patients with a normal D-dimer test and the failure rates were calculated using the conventional (500 μg/L) and the age-adjusted D-dimer cut-off (patient's age x 10 μg/L in patients >50 years).

RESULTS:

In 1672 patients with non-high probability, deep vein thrombosis could be excluded in 850 (51%) patients with the age-adjusted cut-off value versus 707 (42%) patients with the conventional cut-off value. The failure rates were 7 (0.8; 95% confidence interval 0.3-1.7%) for the age-adjusted cut-off value and 5 (0.7%, 0.2-1.6%) for the conventional cut-off value. The absolute increase in patients in whom deep vein thrombosis could be ruled out using the age-adjusted cut-off value was largest in patients >70 years: 19% among patients with non-high probability.

CONCLUSIONS:

The age-adjusted cut-off of the D-dimer combined with clinical probability greatly increases the proportion of older patients in whom deep vein thrombosis can be safely excluded.

• Authors: Renée A Douma, Melanie Tan, Roger E G Schutgens, Shannon M Bates, Arnaud Perrier, Cristina Legnani, Douwe H Biesma, Jeffrey S Ginsberg, Henri Bounameaux, Gualtiero Palareti, Marc Carrier, Gerben C Mol, Grégoire Le Gal, Pieter W Kamphuisen, Marc Righini
• Journal: Haematologica (Haematologica) Vol. 97 Issue 10 Pg. 1507-13 (Oct 2012) ISSN: 1592-8721 [Electronic] Italy
• PMID: 22511491 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Fibrin Fibrinogen Degradation Products
• fibrin fragment D

Topics

• Adult
• Age Factors
• Aged
• Aged, 80 and over
• Cohort Studies
• Female
• Fibrin Fibrinogen Degradation Products
• Humans
• Male
• Middle Aged
• Prognosis
• Reference Values
• Retrospective Studies
• Sensitivity and Specificity
• Venous Thrombosis (blood, diagnosis)