PERC Rule calculator
Result
PERC Negative
All 8 absent — PE excluded without D-dimer (low pre-test probability only)
How to use it
- 1
Establish low pre-test probability first. PERC only valid in patients already at low clinical probability (Wells ≤1 or gestalt <15%).
- 2
All 8 criteria must be absent. Any single positive = PERC positive → D-dimer required.
- 3
PERC negative → discharge. Miss rate ~1.4% in validated low-probability populations.
When to use it
- Young patient with atypical chest pain and Wells ≤1
- PERC negative avoids unnecessary D-dimer and downstream imaging.
- Reducing false-positive D-dimers
- D-dimer elevates with age, infection, pregnancy — PERC prevents unnecessary workup.
- NOT in intermediate/high probability
- Do not apply PERC if Wells >1.
A reference for clinicians and students, not medical advice. A score supports a decision; it does not make one. Check every result against the patient in front of you and your local protocol.
At a glance
- Specialty
- Pulmonology
- Inputs
- 8
- Type
- Points score
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