PERC Rule Calculator
Pulmonary Embolism Rule-out Criteria for low-risk patients.
Important Health Disclaimer
This calculator provides general health information based on standard medical formulas and WHO guidelines. Results are for informational and educational purposes only and should not be considered as professional medical advice, diagnosis, or treatment recommendations.
For health concerns, medical conditions, fitness plans, or dietary decisions, please consult with qualified healthcare professionals, licensed physicians, registered dietitians, or certified fitness trainers who can evaluate your individual health status and medical history.
Individual health needs vary significantly. These calculations are general estimates and may not be appropriate for everyone, especially those with existing medical conditions, pregnant women, children, or elderly individuals.
Not a substitute for professional medical advice
PERC Criteria
If ALL criteria are absent in a low-risk patient, PE can be excluded:
Important Prerequisite
PERC should ONLY be applied to patients already determined to be low-risk by:
- Wells score ≤4 (PE unlikely), OR
- Clinical gestalt <15% probability
PERC Status
PERC Negative
0 of 8 criteria present
Clinical Recommendation
All PERC criteria are negative. In low-risk patients (Wells ≤4 or gestalt <15%), PE can be ruled out without further testing. No D-dimer needed.
PERC Validation
- - Sensitivity: 97.4%
- - Specificity: 21.9%
- - NPV: 99.1%
- - Miss rate: <2% (acceptable threshold)
When NOT to Use PERC
- - Moderate or high-risk patients
- - Clinical gestalt ≥15%
- - Wells score >4
- - Patient with active anticoagulation
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sources
- •World Health Organization (WHO) — Global health metrics, disease classification, and nutritional standards. who.int
- •Centers for Disease Control and Prevention (CDC) — Health statistics, BMI guidelines, and disease prevention data. cdc.gov
- •National Institutes of Health (NIH) — Medical research, clinical guidelines, and health calculators. nih.gov
- •Mayo Clinic — Clinical health information, disease reference, and wellness guidance. mayoclinic.org
For a complete list of all references used across the site, visit our full sources page.
Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
Formula Source: WHO Health Metrics Standards
by World Health Organization