D-dimer concentration increases with age reducing the clinical value of the D-dimer assay in the elderly

Intern Med J. 2007 Sep;37(9):607-13. doi: 10.1111/j.1445-5994.2007.01388.x. Epub 2007 Jun 2.


Background: The D-dimer assay is used as an exclusion test in the assessment of suspected venous thromboembolic disease; patients with a negative result have a low probability of thrombosis. We reviewed the D-dimer results from a hospital and community laboratory using the vidas D-dimer test to assess the influence of age on the D-dimer assay.

Methods: D-dimer results from 6631 unselected patients aged more than 16 years were analysed in four age groups and it was shown that the median D-dimer concentration increased with age (16-40 years, 294 ng/mL; 40-60 years, 387 ng/mL; 60-80 years; 854 ng/mL; >80 years, 1397 ng/mL). To test the effect of age on the assay specificity, a cohort of 1897 patients with suspected venous thromboembolic disease was analysed separately. Patients with a negative D-dimer were discharged without further investigation. Patients with a positive result and a clinical suspicion of thrombosis underwent further investigation. One hundred and sixty-five deep vein thrombosis or pulmonary embolus cases were identified.

Results: The assay specificity decreased with age from 70% in patients less than 40 years to below 5% in patients more than 80 years. Receiver operator curves were prepared for each age group and the effect of altering the threshold value was analysed. In patients 60-80 years old a threshold value of 1000 ng/mL increased assay specificity to 55% without loss of assay sensitivity.

Conclusion: The vidas D-dimer assay with a threshold value of 500 ng/mL has little clinical value as an exclusion test in patients more than 80 years old. The assay specificity is poor (26%) in patients aged 60-80 years but could be improved by increasing the threshold value to 1000 ng/mL. We believe that this should be tested in a prospective trial.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Aging / blood*
  • Biomarkers / blood
  • Clinical Chemistry Tests / standards
  • Cohort Studies
  • Dimerization
  • Female
  • Fibrin Fibrinogen Degradation Products / metabolism*
  • Humans
  • Laboratories, Hospital / standards
  • Male
  • Middle Aged
  • Retrospective Studies
  • Sensitivity and Specificity
  • Thromboembolism / blood
  • Thromboembolism / diagnosis
  • Venous Thrombosis / blood
  • Venous Thrombosis / diagnosis


  • Biomarkers
  • Fibrin Fibrinogen Degradation Products
  • fibrin fragment D