Pneumonia Severity Index (PSI / PORT)
Original two-stage prognostic grouping in adults (age ≥18) with community-acquired pneumonia. This is not an automated admission, diagnosis or treatment rule. Assess oxygenation and clinical deterioration independently.
Complete the fields, then select Calculate.
Step 1: 13 required fields. Tests may follow.
Results
Not calculated: complete required fields and submit.
PSI risk class
Was this calculator easy to use?
Your response is saved to improve this site. Calculator inputs and results are not sent.
Thank you! You can recommend this calculator with the share button above.
Original Fine 1997 two-step algorithm and study limitations
Step 1: Class I
If age ≤50 years, no specified five comorbidities or altered mental status, pulse <125/min, respiratory rate <30/min, systolic BP ≥90 mmHg, and 35 ≤ temperature <40 °C, the subject enters Class I. No numerical score is assigned in this step.
Step 2: points and classes
Otherwise base points are age in years for males or age minus 10 for females, plus the original weights for nursing-home residence, five diseases, vital signs, laboratory findings and effusion. Classes: II ≤70; III 71–90; IV 91–130; V ≥131.
Weights: nursing home +10; neoplasm +30; liver disease +20; heart failure, cerebrovascular disease or renal disease +10 each; altered mental status +20; RR ≥30 +20; SBP <90 +20; temperature <35 or ≥40 +15; pulse ≥125 +10; arterial pH <7.35 +30; BUN ≥30 +20; Na <130 +20; glucose ≥250 +10; hematocrit <30 +10; PaO₂ <60 or SpO₂ <90 +10 (once); pleural effusion +10.
Illustrative examples
Male age 50 without listed risk findings: Class I with no score. Male age 71 without additive findings: 71 points, Class III. Female age 68 with respiratory rate 30 and BUN 30, no other points: 98 points, Class IV.
Original study rates and interpretation
Observed PORT cohort 30-day mortality: Class I 0.1%, II 0.6%, III 0.9%, IV 9.3%, V 27.0%. These are historical cohort observations, NOT individual mortality probabilities. Class I from step one does not exclude hypoxemia or clinical deterioration. Patients receiving respiratory support and other factors require separate clinical judgment; this tool cannot determine admission or therapy.
Sources and review
Original Fine (1997) algorithm; sources checked 2026-11-10.