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Printed on 4/19/2026
For informational purposes only. This is not medical advice.
Age-adjusted D-dimer uses a higher threshold in adults older than 50 years (age × 10 ng/mL FEU) instead of the standard 500 ng/mL FEU cutoff. This improves diagnostic specificity in older populations while preserving safety in low/intermediate pretest probability pathways.
Formula: Age >50: threshold = age × 10 ng/mL FEU; age ≤50: threshold = 500 ng/mL FEU.
Age-adjusted D-dimer thresholds are supported by prospective validation studies for suspected PE pathways.
The calculated threshold indicates whether your D-dimer is below or above age-adjusted rule-out criteria in FEU units. A value below threshold can support PE/DVT exclusion in appropriate low/intermediate pretest settings.
A value at or above threshold does not diagnose VTE by itself; it indicates need for further evaluation per pathway.
Use this tool when applying D-dimer-based PE/DVT rule-out strategies in adults, especially those older than 50 years where fixed cutoffs over-trigger imaging.
Confirm that your assay reports FEU units and that your clinical pathway supports age-adjusted thresholds.
This tool is threshold support only and does not assess pretest probability, instability, or alternative diagnoses. It should not be used as a stand-alone diagnostic decision.
Unit mismatch (FEU vs DDU) can cause major misinterpretation if not verified with local laboratory reporting standards.
For related assessments, see YEARS Algorithm, Wells Score (PE) and Wells Score (DVT).
Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.
Apply the YEARS algorithm with D-dimer to determine whether pulmonary embolism can be ruled out without CTPA.
EmergencyCalculate Wells Score for PE to estimate pretest probability and guide D-dimer testing versus direct CTPA for pulmonary embolism workup.
EmergencyCalculate Wells Score for DVT to estimate pretest probability and guide D-dimer testing, compression ultrasound, and next-step clot workup.
EmergencyUse PERC (Pulmonary Embolism Rule-out Criteria) to rule out PE in low-risk patients without D-dimer or CT when all 8 criteria are negative.