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Updated: Jul 5, 2026

A Multicenter MRI Protocol for the Evaluation and Quantification of Deep Vein Thrombosis
Published on: June 2, 2015
D-dimer testing is useful to exclude deep vein thrombosis in elderly outpatients
M Carrier1, G Le Gal, S M Bates
1Thrombosis Program, Division of Hematology, Department of Medicine, University of Ottawa, Ottawa, ON, Canada.
Background:
Deep vein thrombosis (DVT) can be safely and reliably excluded in patients with a low clinical probability and a negative D-dimer result but the accuracy and utility of such a strategy is unclear in elderly patients.
Objectives:
We sought to compare the performance of the Wells pretest probability (PTP) model and D-dimer testing between patients of different age groups and to examine the utility of the two PTP model classification schemes (low/moderate/high vs. unlikely/likely) in excluding DVT in elderly outpatients.
Patients/Methods:
Pooled analysis of databases from three prospective diagnostic studies evaluating consecutive outpatients with suspected DVT.
Results:
A total of 2696 patients were evaluated. DVT was diagnosed in 400 (15%) patients overall and in 50 out of 325 (15.5%) patients > or = 60 years old. The PTP distribution and the prevalence of DVT in each PTP category were similar among the different age groups. The negative predictive values of a low or unlikely PTP score in combination with a negative D-dimer result were 99% for all groups. A negative D-dimer in combination with a low or unlikely PTP excluded 21.7% and 31% of patients > or = 80 years old, respectively.
Conclusions:
The combination of a low or unlikely PTP with a negative D-dimer result can effectively and safely exclude DVT in a significant proportion of elderly outpatients. However, this clinical prediction rule needs to be prospectively validated with different D-dimer assays in this specific population.
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