What is the clinical evidence from this study?

Study design: Systematic Review. Population: Suspected Acute Venous Thromboembolic Disease (VTE). Intervention: Clinical prediction rules (PERC), age-adjusted D-dimer, and anticoagulation strategies.

What question did this study set out to answer?

This review aims to evaluate the effectiveness of the PERC rule in ruling out pulmonary embolism in low-risk patients.

May 8, 2026

Updated Review of the PERC Rule

Key Result

This clinical policy provides evidence-based recommendations supporting the use of the PERC rule in low-risk patients and age-adjusted D-dimer thresholds in patients over 50 to safely exclude PE.

Key Points

This review aims to evaluate the effectiveness of the PERC rule in ruling out pulmonary embolism in low-risk patients.
Literature review of the PERC rule validation studies
Analysis of pre-test probability definitions and implications
Discussion on the clinical applicability of avoiding unnecessary work-ups
The PERC rule accurately identifies low-risk patients with a less than 2% chance of pulmonary embolism.
Patients with a pre-test probability of less than 15% who meet the PERC criteria require no further testing.

Study Design

Type

Systematic Review

Structured PICO

Can the PERC rule or an age-adjusted D-dimer result safely identify adult ED patients at very low risk for pulmonary embolism for whom no additional diagnostic workup is required?

Population

Adult patients presenting to the emergency department with suspected acute venous thromboembolic disease (pulmonary embolism) with low to intermediate pretest probability.

Intervention

Pulmonary Embolism Rule-out Criteria (PERC) rule for low-risk patients, and age-adjusted D-dimer testing (age x 10 mg/L or age x 5 mg/L depending on assay) for patients older than 50 years.

Comparator

Conventional diagnostic workup, including clinical gestalt assessment or conventional fixed-cutoff D-dimer testing.

Outcome

Missed pulmonary embolism (miss rate/failure rate) and diagnostic accuracy (sensitivity, specificity, negative likelihood ratio).

The ACEP clinical policy recommends the use of the PERC rule and age-adjusted D-dimer cutoffs to safely exclude pulmonary embolism in low-to-intermediate risk ED patients, thereby reducing unnecessary imaging and associated harms.

Limitations

A majority of the studies included were conducted in Europe, where a higher prevalence of PE was reported compared with US populations, limiting applicability.
Some recommendations are based on expert consensus due to a lack of adequate empirical data.
This clinical policy is not intended to represent a legal standard of care for emergency physicians.

Abstract

The Pulmonary Embolism Rule-out Criteria (PERC) rule is a validated clinical tool used to rule out pulmonary embolism (PE) in patients who have a low pre-test probability for PE If a patient is deemed low-risk for PE (pre-test probability <15%) and has no positive criteria on the PERC rule, then no further work-up is needed as the patient has <2% chance of PE.

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