Calculate the PSI/PORT score to assess pneumonia severity and 30-day mortality risk class. Useful for site-of-care review in community-acquired pneumonia.
The Pneumonia Severity Index (PSI), also known as the PORT score, is a validated clinical prediction tool that stratifies patients with community-acquired pneumonia (CAP) into five risk classes based on 30-day mortality. Developed by Fine et al. in 1997 and validated in over 50,000 patients, it remains one of the most widely used tools for site-of-care review in CAP.
The PSI assigns points based on demographics (age, sex), comorbidities (cancer, liver disease, heart failure, cerebrovascular disease, renal disease), physical examination findings (altered mental status, tachypnea, hypotension, temperature extremes, tachycardia), and laboratory/imaging results (pH, BUN, sodium, glucose, hematocrit, PaO2, pleural effusion).
Patients in Risk Classes I and II usually fall into low-risk bands. Class III often lands in an observation-style middle zone, while Classes IV and V represent substantially higher-risk groups. The score is best used to frame care-setting review alongside oxygenation, social factors, oral intake, and the rest of the pneumonia assessment.
The PSI/PORT score is useful because it turns a long CAP severity checklist into one validated mortality-risk class. That makes it easier to discuss whether a case looks outpatient-leaning, observation-level, or inpatient-leaning before the final care-setting decision is made.
This calculator is most helpful as a structured summary of risk, not as a substitute for oxygenation review, social factors, oral tolerance, or the rest of the pneumonia workup.
PSI Score = Age (years, −10 if female) + Nursing home (+10) + Comorbidities (Neoplasm +30, Liver +20, CHF/CVD/Renal +10 each) + Exam (Altered MS +20, RR≥30 +20, SBP<90 +20, Temp <35/≥40 +15, HR≥125 +10) + Labs (pH<7.35 +30, BUN≥30 +20, Na<130 +20, Glucose≥250 +10, Hct<30 +10, PaO₂<60 +10, Effusion +10)
Result: PSI Score: 65, Risk Class II, 30-day mortality 0.6%, outpatient-leaning risk class
A 65-year-old male with no comorbidities or abnormal findings scores 65 points (age alone). This places him in Risk Class II (score ≤ 70) with a predicted 30-day mortality of 0.6%, which is usually read as lower-risk site-of-care context rather than as a stand-alone disposition order.
The PSI works best as a structured mortality-risk summary for community-acquired pneumonia. It is especially strong at identifying lower-risk patients, but it should sit beside oxygenation, oral intake, social support, and the broader bedside assessment.
Age is heavily weighted in PSI, which improves mortality prediction but can make some younger patients with significant acute illness look lower risk than expected. That is why many clinicians compare PSI with simpler severity tools and with their bedside impression.
The PSI does not capture every factor that shapes care-setting review. Immunosuppression severity, multilobar disease burden, inability to take oral therapy, and local follow-up reliability still matter even when the PSI class looks reassuring.
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This page sums the PSI/PORT variables into the standard total score, then maps the total to the usual five risk classes and published 30-day mortality bands. It is meant to keep the demographics, comorbidity, exam, and laboratory pieces in one structured worksheet rather than leaving the score calculation to hand arithmetic.
The result is not a stand-alone disposition rule. PSI is strongest for identifying lower-risk CAP presentations, but oxygen need, oral intake, home support, immunocompromise, and the broader bedside picture still matter beyond the score.
PSI is more comprehensive (20 variables) and better at identifying low-risk patients for outpatient treatment. CURB-65 is simpler (5 variables) and better at identifying high-risk patients. Both are guideline-recommended. PSI may underestimate risk in young patients with severe disease but no comorbidities.
No. The PSI was developed and validated specifically for community-acquired pneumonia. Hospital-acquired and ventilator-associated pneumonia have different risk factors and require different severity assessment tools.
No. PSI should supplement, not replace, clinical judgment. Social factors (homelessness, inability to take oral medications), hypoxia not captured by PaO2, and clinical instability may warrant admission regardless of PSI class.
Age is the baseline for the PSI score because pneumonia mortality increases substantially with age. However, this means young patients with severe disease may be classified as low-risk. Always consider the full clinical picture.
PSI is typically calculated at initial presentation to frame site-of-care review. It is not designed for serial reassessment during hospitalization. For inpatient progress, use clinical stability criteria and the evolving bedside picture instead.
PSI does not capture social determinants of health, ability to take oral medications, oxygenation on room air vs. supplemental O2, multilobar infiltrates, immunosuppression severity, or the causative pathogen. These factors should be considered separately.