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Printed on 7/19/2026
For informational purposes only. This is not medical advice.
The YEARS algorithm is a streamlined PE diagnostic pathway that combines three clinical items with D-dimer thresholds. If none of the YEARS items are present, PE can be ruled out at a D-dimer threshold below 1000 ng/mL FEU. If one or more YEARS items are present, the threshold is below 500 ng/mL FEU. This approach can reduce unnecessary imaging while maintaining safety in appropriate pretest settings.
Formula: If YEARS items = 0, PE ruled out when D-dimer <1000 ng/mL FEU; if YEARS items ≥1, PE ruled out when D-dimer <500 ng/mL FEU.
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Evaluate three simple yes/no items: (1) Clinical signs of DVT — unilateral leg swelling and pain on palpation; (2) PE most likely diagnosis — clinical judgment that PE is the most likely explanation for the presentation; (3) Hemoptysis — coughing up blood. Count the number of positive items (0, 1, 2, or 3).
Draw a high-sensitivity D-dimer assay (FEU units). The YEARS algorithm requires a validated high-sensitivity D-dimer assay — standard-sensitivity assays are not appropriate for the elevated 1000 ng/mL threshold. Confirm which assay your laboratory uses and its validated sensitivity.
If 0 YEARS items are present AND D-dimer is below 1000 ng/mL FEU → PE excluded (no CT-PA needed). If ≥1 YEARS item is present AND D-dimer is below 500 ng/mL FEU → PE excluded (no CT-PA needed). Any other combination (D-dimer above applicable threshold) → CT pulmonary angiography is required.
Emergency physicians, hospitalists
YEARS algorithm provides a validated alternative to the Wells + D-dimer pathway for suspected PE. It uses only 3 clinical items, making it faster to apply at the bedside, and safely excludes approximately 48% of suspected PE patients from needing CT-PA.
Emergency departments, radiology stewardship programs
In the YEARS study (Lancet 2017), 48% of patients were safely excluded from CT-PA using YEARS, compared to 34% with the standard Wells + D-dimer algorithm — a 14% absolute reduction in CT-PA utilization without a meaningful increase in missed PE events.
Obstetricians, emergency physicians, maternal-fetal medicine
The pregnancy-adapted YEARS algorithm (van der Pol et al., NEJM 2019) safely excluded PE in pregnant women with 0 YEARS items and D-dimer below 1000 ng/mL, reducing CT-PA and V/Q scan exposure compared to standard algorithms. This is particularly valuable given the fetal radiation exposure concern.
High-volume emergency departments
In busy emergency settings with high PE evaluation volumes, YEARS algorithm's 3-item structure enables rapid, structured evaluation. The elevated 1000 ng/mL D-dimer threshold for 0-item patients substantially reduces lab-to-decision time by avoiding CT-PA in a larger proportion of low-risk patients.
Radiology departments, quality improvement teams
By applying a more selective threshold for CT-PA, YEARS algorithm improves the pretest probability of positive CT-PA findings — meaning fewer unnecessary studies with normal results. This has cost, workflow, and patient safety implications (contrast exposure, incidental findings).
In the YEARS prospective study of 3,616 patients, 48% were safely discharged without CT-PA using YEARS, compared to 34% with the standard Wells + fixed D-dimer algorithm. The absolute difference — 14% more CT-PA-free evaluations — is clinically and operationally significant.
YEARS' most important feature is raising the D-dimer threshold to 1000 ng/mL in 0-item patients while keeping it at 500 ng/mL in ≥1-item patients. This asymmetric threshold is what enables greater CT-PA avoidance without compromising safety compared to a uniform 500 ng/mL cutoff.
The YEARS algorithm was validated with high-sensitivity D-dimer assays. Using a standard-sensitivity assay at the elevated 1000 ng/mL threshold may not be appropriate — confirm your laboratory uses a high-sensitivity FEU assay before applying YEARS. The assay's analytical sensitivity and clinical validation directly affect safety.
The pregnancy-adapted YEARS algorithm (van der Pol et al., NEJM 2019) applies the same 0-item 1000 ng/mL threshold to pregnant women with suspected PE and safely avoids CT-PA and V/Q in 39% of cases. This is currently one of the best-validated PE algorithms for pregnant patients.
If clinical signs of DVT are present (one of the YEARS items), bilateral compression ultrasound can be performed simultaneously with D-dimer. Confirmed DVT in a patient with suspected PE permits anticoagulation initiation without CT-PA, and its presence influences the YEARS item scoring.
CT-PA delivers approximately 4–5 mSv of thoracic radiation. For women of reproductive age or pregnant patients, this exposure is clinically relevant. YEARS algorithm's ability to safely reduce CT-PA use is particularly valuable in these populations.
The 'PE most likely diagnosis' item is the only subjective element in YEARS. While it introduces some inter-rater variability, it correlates well with clinician gestalt and was found to have acceptable reproducibility in the YEARS study. Trainee providers should discuss this item with an attending when uncertain.
In the YEARS study, 3-month VTE recurrence or PE-related death occurred in only 0.04% of patients excluded from CT-PA using YEARS (6 of 1651 patients). The algorithm's sensitivity for PE is approximately 97.5%, comparable to traditional Wells + D-dimer approaches.
In hemodynamically unstable patients with high clinical suspicion for massive PE, do not delay anticoagulation (or thrombolysis) while waiting for CT-PA results. YEARS algorithm is designed for hemodynamically stable suspected PE — it is not appropriate for patients in shock.
YEARS Algorithm published by van der Hulle et al. (YEARS Study Group, Lancet 2017) from 3616 patients. 48% excluded from CT-PA vs 34% with standard Wells algorithm; non-inferiority confirmed (1 failure per 1000 patient-years). Pregnancy-adapted YEARS: van der Pol et al. (NEJM 2019). ESC 2019 PE Guidelines reference YEARS as an alternative diagnostic strategy. D-dimer of 1000 ng/mL for 0-YEARS-item patients validated at high-sensitivity assay threshold.
The YEARS result indicates whether PE can be ruled out based on the number of YEARS clinical items and the corresponding D-dimer threshold. When below threshold, imaging is often avoidable; when at or above threshold, PE is not ruled out and imaging is usually required.
This is a diagnostic pathway tool and should be integrated with overall pretest assessment and local protocol.
Use YEARS when evaluating suspected PE in adults where a structured D-dimer-first pathway is appropriate. It is useful in ED and acute-care settings to reduce unnecessary CTPA while maintaining safety.
Apply only when the clinical scenario fits intended diagnostic use and no immediate hemodynamic instability mandates urgent imaging.
YEARS performance depends on correct clinical assessment of its subjective items, especially whether PE is most likely. Misclassification can alter thresholds and downstream decisions.
It should not be used as a stand-alone decision in unstable patients or when local assay units/thresholds are not aligned with pathway standards.
For related assessments, see Wells Score (PE), PERC Rule and Age-Adjusted D-dimer.
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.
April 21, 2026 · trust-baseline
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