PSI Port Score Calculator
Stratify pneumonia severity using the Pneumonia Severity Index for disposition decisions. Enter values for instant results with step-by-step formulas.
Reviewed by Rahul Singh, Health & Wellness Specialist
Formula
PSI = Age + Sex Modifier + Nursing Home + Comorbidities + Physical Exam + Lab/Radiology Findings
The PSI sums points from 20 variables: age in years (minus 10 for females), nursing home residence (+10), comorbidities (neoplastic +30, liver +20, CHF/CVD/renal +10 each), physical exam findings (altered mental status +20, RR>=30 +20, SBP<90 +20, temp abnormal +15, pulse>125 +10), and lab/radiology (pH<7.35 +30, BUN>30 +20, Na<130 +20, glucose>250 +10, Hct<30 +10, PaO2<60 +10, effusion +10).
Worked Examples
Example 1: Elderly Male with Multiple Comorbidities
Problem:A 78-year-old male nursing home resident with CHF presents with pneumonia. Altered mental status, RR 32, BP 85/50, temp 38.5C, pulse 130. Labs: BUN 35, Na 128, pH 7.30, PaO2 55. Pleural effusion present.
Solution:Age: +78\nSex (male): +0\nNursing home: +10\nCHF: +10\nAltered mental status: +20\nRR >= 30: +20\nSBP < 90: +20\nTemp (normal range): +0\nPulse > 125: +10\npH < 7.35: +30\nBUN > 30: +20\nNa < 130: +20\nPaO2 < 60: +10\nPleural effusion: +10\nTotal: 258 points
Result:PSI Score: 258 | Class V | Mortality: 27-31% | Hospitalize, consider ICU
Example 2: Young Healthy Female
Problem:A 32-year-old female with no comorbidities, no nursing home, normal mental status, RR 20, BP 120/78, temp 38.8C, pulse 96.
Solution:Age <= 50: Check Class I criteria\nNo comorbidities: Yes\nStable vital signs (no altered mental status, RR < 30, SBP >= 90, pulse <= 125): Yes\nMeets all Class I criteria
Result:PSI Class I | Mortality: 0.1% | Outpatient treatment with oral antibiotics
Frequently Asked Questions
What is the PSI/PORT score and how was it developed?
The Pneumonia Severity Index (PSI), also known as the PORT score (Patient Outcomes Research Team), is a clinical prediction tool developed by Dr. Michael Fine and colleagues in 1997 to stratify the severity of community-acquired pneumonia. It was derived from a cohort of 14,199 hospitalized pneumonia patients and validated in 38,039 additional patients across multiple institutions. The PSI uses 20 variables spanning demographics, comorbidities, physical examination findings, and laboratory or radiographic results to calculate a composite score. This score assigns patients to one of five risk classes that predict 30-day mortality, ranging from 0.1 percent in Class I to over 27 percent in Class V.
How are PSI risk classes defined and what do they mean?
The PSI divides patients into five risk classes based on total points. Class I includes patients age 50 or younger with no comorbidities and stable vital signs, assigned automatically without scoring. Class II includes patients with 70 points or fewer and has a mortality rate of approximately 0.6 percent. Class III encompasses scores from 71 to 90 with mortality of 0.9 to 2.8 percent. Class IV includes scores from 91 to 130 with mortality of 8.2 to 9.3 percent. Class V covers scores above 130 with mortality of 27.0 to 31.1 percent. Classes I through III are generally considered low risk and potentially suitable for outpatient management.
Which comorbidities does the PSI score include and how are they weighted?
The PSI assigns different point values to five specific comorbidities. Neoplastic disease, defined as any cancer except basal or squamous cell skin cancer that was active at diagnosis or treated within the past year, receives the highest weight at 30 points. Liver disease, including clinical or histologic diagnosis of cirrhosis or other forms of chronic liver disease, adds 20 points. Congestive heart failure, cerebrovascular disease, and renal disease each contribute 10 points. These comorbidities were selected because they independently predicted mortality in the original derivation cohort. Other conditions like diabetes or COPD are not included because they did not significantly predict 30-day mortality after adjustment.
How does the PSI score handle age and sex?
Age is the most heavily weighted demographic variable in the PSI score. For male patients, the age in years is added directly to the score, so a 75-year-old male automatically starts with 75 points. For female patients, 10 points are subtracted from their age before adding it to the score, reflecting the finding that women with pneumonia have slightly lower mortality than men of the same age. This means a 75-year-old female would contribute 65 points from the age component. The age adjustment reflects biological differences in pneumonia outcomes observed in the derivation cohort. Nursing home residence adds an additional 10 points regardless of sex.
References
Reviewed by Rahul Singh, Health & Wellness Specialist · Editorial policy