What are the limitations of the years algorithm?

While the years algorithm is highly validated, it should not replace clinical judgment. OpiCalc provides the latest evidence-based limitations for the years algorithm to ensure safe bedside use and optimal diagnostic accuracy.

How does the years algorithm compare to other Hematology scores?

The years algorithm is a gold-standard diagnostic tool. OpiCalc provides side-by-side clinical guidance to help clinicians choose the most specific evidence-based tool for their patient's presentation.

Is the years algorithm free to use?

Yes. OpiCalc provides the years algorithm completely ad-free and optimized for mobile bedside use, ensuring you can calculate medical risk swiftly and without distraction.

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YEARS Algorithm

YEARS Concept: Dynamic D-dimer adjustment. If NONE of the 3 clinical items are present, the rule-out threshold is elevated to 1000 µg/L.

1. YEARS Items

2. D-dimer Result

µg/L (FEU)

Awaiting Values

Guidelines & Evidence

Clinical Details

Section 1

When to Use

Ruling out Pulmonary Embolism (PE) using a simplified, variable D-dimer threshold.

Reducing unnecessary CTPA scans in patients with suspected PE.

Particularly useful in younger patients and pregnant patients (modified version).

The Core Concept

The YEARS algorithm adjusts the D-dimer threshold to 1000 µg/L if zero clinical signs are present, effectively doubling the standard "rule-out" range for low-risk patients.

Section 2

Formula & Logic

YEARS Items (Check for Presence)

Clinical signs of DVT (e.g., unilateral leg swelling, tenderness).

Hemoptysis (coughing up blood).

PE is the MOST likely diagnosis.

D-dimer Thresholds

YEARS Items Found	Threshold (µg/L)	Clinical Action
0 Items	< 1000	PE Ruled Out
≥ 1 Item	< 500	PE Ruled Out
0 Items	≥ 1000	CTPA Indicated
≥ 1 Item	≥ 500	CTPA Indicated

Section 3

Pearls/Pitfalls

Efficiency Gain

Prospective validation showed that the YEARS algorithm led to a 14% absolute reduction in CTPA scans compared to standard Wells/fixed-D-dimer triage, with a 3-month VTE failure rate of only 0.61%.

Gestalt Integration

The "most likely diagnosis" criterion integrates the clinician's experience directly into the laboratory threshold. If your gut feeling is PE, you must use the stricter 500 µg/L cutoff.

Section 4

Evidence Appraisal

Primary Strategy

Simplified diagnostic management of suspected pulmonary embolism (the YEARS study): a prospective, multicentre, cohort study.

van der Hulle T et al. • The Lancet. 2017;390(10091):289-297.

View Source

Section 5

Literature

Development

Developed by the Leiden University Medical Center group to simplify PE triage into three easily remembered clinical questions.

Last Comprehensive Review: 2026

Guidelines & Evidence

Clinical Details

Section 1

When to Use

Ruling out Pulmonary Embolism (PE) using a simplified, variable D-dimer threshold.

Reducing unnecessary CTPA scans in patients with suspected PE.

Particularly useful in younger patients and pregnant patients (modified version).

The Core Concept

The YEARS algorithm adjusts the D-dimer threshold to 1000 µg/L if zero clinical signs are present, effectively doubling the standard "rule-out" range for low-risk patients.

Section 2

Formula & Logic

YEARS Items (Check for Presence)

Clinical signs of DVT (e.g., unilateral leg swelling, tenderness).

Hemoptysis (coughing up blood).

PE is the MOST likely diagnosis.

D-dimer Thresholds

YEARS Items Found	Threshold (µg/L)	Clinical Action
0 Items	< 1000	PE Ruled Out
≥ 1 Item	< 500	PE Ruled Out
0 Items	≥ 1000	CTPA Indicated
≥ 1 Item	≥ 500	CTPA Indicated

Section 3

Pearls/Pitfalls

Efficiency Gain

Prospective validation showed that the YEARS algorithm led to a 14% absolute reduction in CTPA scans compared to standard Wells/fixed-D-dimer triage, with a 3-month VTE failure rate of only 0.61%.

Gestalt Integration

The "most likely diagnosis" criterion integrates the clinician's experience directly into the laboratory threshold. If your gut feeling is PE, you must use the stricter 500 µg/L cutoff.

Section 4

Evidence Appraisal

Primary Strategy

Simplified diagnostic management of suspected pulmonary embolism (the YEARS study): a prospective, multicentre, cohort study.

van der Hulle T et al. • The Lancet. 2017;390(10091):289-297.

View Source

Section 5

Literature

Development

Developed by the Leiden University Medical Center group to simplify PE triage into three easily remembered clinical questions.

Last Comprehensive Review: 2026

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YEARS Algorithm

YEARS Concept: Dynamic D-dimer adjustment. If NONE of the 3 clinical items are present, the rule-out threshold is elevated to 1000 µg/L.

1. YEARS Items

2. D-dimer Result

µg/L (FEU)

Awaiting Values

Guidelines & Evidence

Clinical Details

Section 1

When to Use

Ruling out Pulmonary Embolism (PE) using a simplified, variable D-dimer threshold.

Reducing unnecessary CTPA scans in patients with suspected PE.

Particularly useful in younger patients and pregnant patients (modified version).

The Core Concept

The YEARS algorithm adjusts the D-dimer threshold to 1000 µg/L if zero clinical signs are present, effectively doubling the standard "rule-out" range for low-risk patients.

Section 2

Formula & Logic

YEARS Items (Check for Presence)

Clinical signs of DVT (e.g., unilateral leg swelling, tenderness).

Hemoptysis (coughing up blood).

PE is the MOST likely diagnosis.

D-dimer Thresholds

YEARS Items Found	Threshold (µg/L)	Clinical Action
0 Items	< 1000	PE Ruled Out
≥ 1 Item	< 500	PE Ruled Out
0 Items	≥ 1000	CTPA Indicated
≥ 1 Item	≥ 500	CTPA Indicated

Section 3

Pearls/Pitfalls

Efficiency Gain

Prospective validation showed that the YEARS algorithm led to a 14% absolute reduction in CTPA scans compared to standard Wells/fixed-D-dimer triage, with a 3-month VTE failure rate of only 0.61%.

Gestalt Integration

The "most likely diagnosis" criterion integrates the clinician's experience directly into the laboratory threshold. If your gut feeling is PE, you must use the stricter 500 µg/L cutoff.

Section 4

Evidence Appraisal

Primary Strategy

Simplified diagnostic management of suspected pulmonary embolism (the YEARS study): a prospective, multicentre, cohort study.

van der Hulle T et al. • The Lancet. 2017;390(10091):289-297.

View Source

Section 5

Literature

Development

Developed by the Leiden University Medical Center group to simplify PE triage into three easily remembered clinical questions.

Last Comprehensive Review: 2026

Guidelines & Evidence

Clinical Details

Section 1

When to Use

Ruling out Pulmonary Embolism (PE) using a simplified, variable D-dimer threshold.

Reducing unnecessary CTPA scans in patients with suspected PE.

Particularly useful in younger patients and pregnant patients (modified version).

The Core Concept

The YEARS algorithm adjusts the D-dimer threshold to 1000 µg/L if zero clinical signs are present, effectively doubling the standard "rule-out" range for low-risk patients.

Section 2

Formula & Logic

YEARS Items (Check for Presence)

Clinical signs of DVT (e.g., unilateral leg swelling, tenderness).

Hemoptysis (coughing up blood).

PE is the MOST likely diagnosis.

D-dimer Thresholds

YEARS Items Found	Threshold (µg/L)	Clinical Action
0 Items	< 1000	PE Ruled Out
≥ 1 Item	< 500	PE Ruled Out
0 Items	≥ 1000	CTPA Indicated
≥ 1 Item	≥ 500	CTPA Indicated

Section 3

Pearls/Pitfalls

Efficiency Gain

Prospective validation showed that the YEARS algorithm led to a 14% absolute reduction in CTPA scans compared to standard Wells/fixed-D-dimer triage, with a 3-month VTE failure rate of only 0.61%.

Gestalt Integration

The "most likely diagnosis" criterion integrates the clinician's experience directly into the laboratory threshold. If your gut feeling is PE, you must use the stricter 500 µg/L cutoff.

Section 4