The YEARS algorithm is a simplified clinical decision tool used to safely rule out pulmonary embolism (PE) and reduce the need for unnecessary CT scans.)
The YEARS algorithm is a validated clinical decision rule that simplifies the diagnostic workup for suspected pulmonary embolism (PE) by combining three high-yield clinical criteria with variable D-dimer thresholds, allowing PE to be safely excluded in more patients without CT pulmonary angiography (CTPA).
YEARS distills the Wells score down to the three most predictive items and uses them to stratify patients into low vs. higher pretest probability, then applies **different D-dimer cutoffs accordingly:
The algorithm evaluates three specific signs and symptoms:Clinical signs of deep vein thrombosis (DVT)Hemoptysis (coughing up blood):Pulmonary embolism as the most likely diagnosis.
YEARS items (count 0–3): 1. Clinical signs or symptoms of deep vein thrombosis (DVT) 2. Hemoptysis 3. PE is the most likely diagnosis (clinical judgment)
D-Dimer Threshold-Based on how many of the three criteria are met, the pathway uses a variable D-dimer cutoff to determine the next step:0 criteria met: PE is excluded if the D-dimer level is < 1000 ng/mL.1 or more criteria met: PE is excluded if the D-dimer level is < 500 ng/mL.
If the D-dimer is below the respective threshold for score, no further imaging is needed.If the D-dimer is above the threshold, a CT pulmonary angiogram (CTPA) is recommended.
The tool can also be adapted for use in pregnant patients, and patients with cancer.
D-dimer thresholds:
0 YEARS items present: PE can be excluded if D-dimer <1,000 ng/mL
≥1 YEARS item present: pPE can be excluded if D-dimer <500 ng/mL
If D-dimer is ≥ 1000 the applicable threshold-proceed to imaging (typically CTPA).
In practice:
0 items + D-dimer <1,000 → PE ruled out, no CTPA
≥1 item + D-dimer <500→ PE ruled out, no CTPA
Initial study reported approximately: Sensitivity ~98% Negative predictive value ~99% Specificity ~55%
A 2024 systematic review/meta‑analysis found: Sensitivity 96% (95% CI 93–98%) Specificity 50% (95% CI 33–67%) Advanced imaging utilization reduced (risk ratio ~0.78)
Implementation studies also show shorter ED length of stay and earlier anticoagulation in confirmed PE when using YEARS versus conventional pathways.
YEARS is intended for hemodynamically stable adults with suspected PE as part of a structured pathway:
A pregnancy-adapted YEARS algorithm has been validated and shown to safely rule out PE in pregnant patients with suspected PE, using the same three items with pregnancy-specific D-dimer considerations.
Active cancer:Recent randomized noninferiority data have evaluated YEARS in patients with active cancer to assess safety and efficiency versus standard CTPA-based pathways.