Healthcare & Clinical Formulas
YEARS Algorithm for Pulmonary Embolism: Dynamic D-Dimer Cutoff (1000 vs 500)
Evaluate Tom van der Hulle’s 3-item YEARS pulmonary embolism rule (DVT signs, hemoptysis, PE most likely diagnosis) and dynamic D-dimer threshold (< 1,000 ng/mL if 0 YEARS items vs < 500 ng/mL if >= 1 YEARS item) to safely reduce unnecessary CTPA scans.
How YEARS safely avoids 14% of chest CT angiograms with simultaneous D-dimer testing!
Traditional Wells/Geneva workflows order D-dimer only in low-probability patients at a rigid 500 ng/mL FEU cutoff—sending thousands of emergency patients with mildly elevated D-dimer (500–999 ng/mL) to unnecessary radiation and contrast CT Pulmonary Angiography (CTPA)! Tom van der Hulle et al. (The Lancet, 2017; 3,465 suspected PE patients) validated the streamlined YEARS Algorithm using simultaneous D-dimer plus just THREE highest-yield Wells items: (1) Clinical signs of DVT, (2) Hemoptysis, and (3) Pulmonary Embolism is the most likely diagnosis!
The YEARS cutoff rule is crystal clear: when ZERO YEARS items are present (YEARS = 0), PE is safely ruled out if D-dimer < 1,000 ng/mL FEU; when 1 or more YEARS items are present (YEARS >= 1), PE is ruled out only if D-dimer < 500 ng/mL FEU; if D-dimer meets or exceeds the active threshold, order CTPA! Watch a patient with D-dimer = 740 ng/mL: at YEARS = 0 (< 1,000 cutoff), PE is safely ruled out without CTPA; if "PE most likely" is checked (YEARS = 1 -> 500 cutoff), 740 >= 500 triggers CTPA!
| YEARS Item Count (0–3) | Active D-Dimer Rule-Out Cutoff | Example D-Dimer = 740 ng/mL | 3-Month VTE Miss Rate |
|---|---|---|---|
| 0 YEARS Items Present | < 1,000 ng/mL FEU | PE Ruled Out — No CTPA Needed! | 0.4% (Well Below 2% Safety Bar) |
| >= 1 YEARS Item Present | < 500 ng/mL FEU | 740 >= 500 -> Order CTPA! | 0.8% Overall Cohort |
| Any YEARS Count + D-Dimer = 380 ng/mL | < 500 (and < 1,000) | PE Ruled Out — No CTPA Needed! | Universal Low D-Dimer Clearance |
Dynamic YEARS D-Dimer Threshold (1,000 vs 500 ng/mL FEU)
Validates binary 0/1 flags across the 3 YEARS items B2:B4 and returns 1000 when SUM(B2:B4) = 0 or 500 when SUM(B2:B4) >= 1.
=IF(OR(COUNTA(B2:B4) < 3, SUMPRODUCT((B2:B4 <> 0) * (B2:B4 <> 1)) > 0, B5 < 0), "Invalid YEARS Input", IF(SUM(B2:B4) = 0, 1000, 500))YEARS Algorithm CTPA Imaging vs PE Rule-Out Disposition
Compares quantitative D-dimer B5 (ng/mL FEU) against the dynamic 1,000 / 500 ng/mL cutoff.
=IF(OR(COUNTA(B2:B4) < 3, SUMPRODUCT((B2:B4 <> 0) * (B2:B4 <> 1)) > 0, B5 < 0), "Invalid YEARS Input", IF(B5 < IF(SUM(B2:B4) = 0, 1000, 500), "PE Ruled Out (No CTPA Needed)", "CTPA Indicated (D-Dimer >= Cutoff)"))Try the example
Use the original values or change them to test your understanding.