Age_adjusted_d_dimer_for_venous_thromboembolism_vte v.0
The goals of the age-adjusted D-dimer is to increase the specificity of the test in patients ≥50 years old and prevent unnecessary testing and complications. Adjusts D-dimer cutoffs by age to help rule out VTE.
The goals of the age-adjusted D-dimer is to increase the specificity of the test in patients ≥50 years old and prevent unnecessary testing and complications. Adjusts D-dimer cutoffs by age to help rule out VTE.
Patients ≥50 years old presenting to emergency department as outpatients who are being worked up for PE and have low to intermediate pretest probability. Has been shown to significantly increase specificity in older populations with minimal reduction in sensitivity. Can be used for assays that report fibrinogen equivalent units (FEU) with a D-dimer cutoff of 500 µg/L, or D-dimer units (DDU, less common) with a D-dimer cutoff of 250 µg/L. A value below age x 10 µg/L (5 µg/L for DDU assays) adequately rules out the need for further testing for PE in low- to intermediate-risk patients. Note: there is currently no standard D-dimer unit of measure, and there is wide variation among labs in cutoffs reported and magnitude of unit (e.g. µg/L vs ng/mL vs µg/mL). Interpretation: Age-adjusted D-dimer is above cutoff. VTE diagnosis is likely. Recommendation: Consider confirmatory testing with CTA or V/Q scan. Age-adjusted D-dimer is at or below cutoff. VTE diagnosis is unlikely. Recommendation: Consider alternative diagnosis.
Should only be used in patients ≥50 years of age. Check your lab result carefully for unit of measure (e.g. μg/L or ng/mL vs µg/mL) and type of unit (FEU vs DDU). Use of the age-adjusted D-dimer is not appropriate for patients who are high-risk based on clinical gestalt or clinical prediction scores, such as the Wells’ Score for PE (scores >4) or Revised Geneva Score (scores >11).
1. Schouten HJ, Geersing GJ, Koek HL, Zuithoff NP, Janssen KJ, Douma RA, van Delden JJ, Moons KG, Reitsma JB. Diagnostic accuracy of conventional or age adjusted D-dimer cut-off values in older patients with suspected venous thromboembolism: systematic review and meta-analysis. Bmj. 2013 May 3;346:f2492.
OBSERVATION.basic_demographic.v1, EVALUATION.age_adjusted_d_dimer_for_venous_thromboembolism_vte.v0, OBSERVATION.lab_test_d_dimer.v0
