Tested on Gulf Medical Boards (DHA, SMLE, MOH & HAAD)
Clinical calculations and diagnostic scoring systems like Pneumonia Severity Index (PSI/PORT) frequently appear on Prometric exams. Master high-yield clinical vignettes with instant AI-powered pathophysiology rationales.
What is the Pneumonia Severity Index (PSI/PORT)?
The Pneumonia Severity Index (PSI/PORT) is an evidence-based clinical decision rule engineered to quantify diagnostic probability, stratify clinical severity, and guide therapeutic decision-making in pulmonology practice. The Pneumonia Severity Index (PSI), also known as the PORT score, is a highly validated clinical prediction rule used to calculate the probability of morbidity and mortality among patients with community-acquired pneumonia (CAP). It helps clinicians decide whether patients can be safely treated as outpatients. Clinical scoring tools like Pneumonia Severity Index (PSI/PORT) are essential in acute and outpatient management, enabling clinicians to objectively differentiate between low-risk candidates suitable for conservative therapy and high-risk patients requiring urgent interventions. Verified against current 2026 clinical standards, this tool is extensively tested on Gulf health authority licensing exams including DHA (Dubai), SMLE (Saudi Arabia), MOH, HAAD/DOH (Abu Dhabi), OMSB (Oman), and QCHP (Qatar).
💡Clinical Pearls & Diagnostic Utility
Provides more granular risk stratification than CURB-65. The IDSA/ATS guidelines recommend the PSI over CURB-65 for determining site of care in CAP.
Formula & Calculation Parameters
The mathematical equation and clinical variables required to calculate Pneumonia Severity Index (PSI/PORT):
Score Interpretation & Clinical Stratification
| Score Range | Clinical Interpretation | Risk Tier |
|---|---|---|
| ≤ 70 | Risk Class II (Low) | green |
| 71 – 90 | Risk Class III (Low) | yellow |
| 91 – 130 | Risk Class IV (Moderate) | orange |
| ≥ 131 | Risk Class V (High) | red |
When to Exercise Caution
Heavily weighted by age, which may underestimate risk in young patients with severe hypoxemia or sepsis, and overestimate risk in healthy elderly patients. Requires extensive lab testing.
Clinical Review Board
Dr. Muhammad Nouman, MBBS
Capital Medical University | PMDC Reg No: 117744-P
Clinical Audit Status
✓ Verified for 2026 Guidelines
Last updated: 2026-08-07
Peer-Reviewed Medical Literature
- •Fine MJ, Auble TE, Yealy DM, et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med. 1997;336(4):243-250.
Related Pulmonology Calculators & Scoring Tools
Explore related clinical calculators, risk stratification indexes, and diagnostic scoring algorithms in Pulmonology:
Wells' Criteria for DVT
Calculates the pre-test probability of Deep Vein Thrombosis.
Glasgow Coma Scale (GCS)
Assesses the level of consciousness after neurological injury.
qSOFA Score
Quick Sequential Organ Failure Assessment for sepsis risk.
Centor Score
Estimates probability of streptococcal pharyngitis.
Mean Arterial Pressure (MAP)
Calculate MAP based on Systolic and Diastolic Blood Pressure.
CURB-65 Score for Pneumonia
Estimates mortality of community-acquired pneumonia to help determine inpatient vs. outpatient treatment.