Age-Adjusted D-Dimer Cutoff Levels to Rule Out Deep Vein Thrombosis

The age-adjusted D-dimer cutoff (age × 10 µg/L in patients 50 years or older), safely increases the diagnostic yield of D-dimer in patients with suspected pulmonary embolism but has not been validated in patients with suspected leg deep vein thrombosis (DVT).

To prospectively validate whether using an age-adjusted D-dimer cutoff allows clinicians to safely rule out DVT. Design, Setting, and Patients: Multicenter, multinational prospective management outcome study conducted in 27 centers in Belgium, Canada, France, and Switzerland between January 2015 and October 2022 (last follow-up visit, January 30, 2023) and including outpatients presenting to the emergency department with suspected DVT. Interventions: Patients were assessed by a sequential diagnostic strategy based on the assessment of clinical pretest probability by the Wells score, a highly sensitive D-dimer test, and leg compression ultrasonography. Patients in whom DVT was ruled out were followed up for a 3-month period. Main Outcome and Measure: The primary outcome was the rate of adjudicated symptomatic venous thromboembolic events during follow-up in patients in whom DVT was ruled out based on a D-dimer value between the conventional cutoff of 500 µg/L and their age-adjusted cutoff.