Low Wells → PERC · Moderate Wells → D-dimer (YEARS + ADJUST-PE) · High Wells → CTA
1Wells Score for PE
Clinical signs and symptoms of DVT
Leg swelling, tenderness along deep venous system
+3
PE is #1 diagnosis OR equally likely
As determined by clinical judgment
+3
Heart rate > 100 bpm
+1.5
Immobilization ≥ 3 days OR surgery in previous 4 weeks
+1.5
Previous DVT or PE
+1.5
Hemoptysis
+1
Malignancy (on treatment, treated in last 6 mo, or palliative)
+1
WELLS SCORE
0
—
2PERC Rule (Low risk only — Wells ≤ 2)
All 8 must be ABSENT to rule out PE without D-dimer. Skip PERC if moderate risk (Wells > 2) — proceed to D-dimer.
Age ≥ 50 years
Heart rate ≥ 100 bpm
SpO₂ < 95% on room air
Unilateral leg swelling
Hemoptysis
Recent trauma or surgery (within 4 weeks)
Prior DVT or PE
Exogenous estrogen (OCP, HRT, SERM)
PERC positive items: 0
3YEARS Criteria
Clinical signs of DVT
Hemoptysis
PE most likely diagnosis
YEARS criteria met: 0
4D-Dimer & Age-Adjusted Threshold
Age must be between 1 and 120.
D-dimer must be between 0 and 50,000 µg/L.
Age-adjusted D-dimer threshold (ADJUST-PE):
Age × 10 µg/L for patients > 50 years (standard threshold 500 µg/L if ≤ 50)
Result
Evidence Base
Wells PS, et al. Derivation of a simple clinical model to categorize patients probability of pulmonary embolism. Thromb Haemost 1998. PMID 9798506
Kline JA, et al. Clinical criteria to prevent unnecessary diagnostic testing in ED patients with suspected PE. J Thromb Haemost 2004. PMID 15304025 (PERC)
van der Hulle T, et al. Simplified diagnostic management of suspected PE (YEARS study). Lancet 2017. PMID 28549662
Righini M, et al. Age-adjusted D-dimer cutoff levels to rule out pulmonary embolism (ADJUST-PE). JAMA 2014. PMID 24643601
Konstantinides SV, et al. 2019 ESC Guidelines for acute PE. Eur Heart J 2020. PMID 31504429
Raja AS, et al. Evaluation of patients with suspected acute PE. NEJM 2013. PMID 23984730
YBEMUS · Guy Youngblood, MD, FACEP, FAAEM
CCEMRP · BCM/CHRISTUS Children's PEM Fellowship
For educational use. Not a substitute for clinical judgment.