PSI Score Calculator
Complete all sections. Demographic factors calculated automatically. Tick clinical findings present.
Step 1 — Demographics
years
✓
Nursing home resident
+10
Step 2 — Comorbid Illnesses
✓
Active neoplastic disease
Any cancer except basal cell carcinoma of skin, active/treated in past year
+30
✓
Liver disease
Cirrhosis or chronic active hepatitis
+20
✓
Congestive heart failure
+10
✓
Cerebrovascular disease
Prior stroke or TIA
+10
✓
Renal disease
Chronic dialysis or elevated creatinine >1.2 mg/dL at baseline
+10
Step 3 — Physical Examination
✓
Altered mental status
Disorientation, stupor, or coma (not baseline)
+20
✓
Respiratory rate ≥30 breaths/min
+20
✓
Systolic BP <90 mmHg
+20
✓
Temperature <35°C or ≥40°C
+15
✓
Heart rate ≥125 bpm
+10
Step 4 — Lab & Imaging Findings
✓
Arterial pH <7.35
+30
✓
BUN ≥30 mg/dL (≥10.7 mmol/L)
+20
✓
Sodium <130 mmol/L
+20
✓
Glucose ≥250 mg/dL (≥13.9 mmol/L)
+10
✓
Haematocrit <30%
+10
✓
PaO₂ <60 mmHg or SpO₂ <90% on room air
+10
✓
Pleural effusion on imaging
+10
PSI Score (before age)
0
pts
—
—
PSI Score
—
points
Risk Class
—
I–V
30-Day Mortality
—
%
PSI Risk Classes & Mortality
| Class | Score | 30-Day Mortality | Recommended Setting |
|---|---|---|---|
| I | Age ≤50 + no comorbidities + no abnormal signs | 0.1% | Outpatient |
| II | ≤70 | 0.6% | Outpatient |
| III | 71–90 | 2.8% | Outpatient or brief inpatient |
| IV | 91–130 | 8.2% | Inpatient |
| V | >130 | 29.2% | Inpatient (consider ICU) |
CAP Antibiotic Recommendations — IDSA/ATS 2019
- Outpatient (Class I–III), previously healthy, no recent antibiotics: Amoxicillin 500 mg TDS × 5 days. Or doxycycline 100 mg BD × 5 days (atypical cover). Azithromycin if low local pneumococcal resistance
- Outpatient with comorbidities (diabetes, heart/lung/liver/renal disease, immunosuppression): Amoxicillin-clavulanate 875/125 mg BD + azithromycin 500 mg OD × 5 days. Or respiratory fluoroquinolone (levofloxacin 750 mg OD × 5 days)
- Inpatient, non-ICU (Class IV): IV β-lactam (ampicillin-sulbactam 3g QID, or ceftriaxone 1–2g OD) + azithromycin 500 mg OD. Or respiratory fluoroquinolone monotherapy
- ICU (Class V, severe CAP): IV β-lactam + IV azithromycin or IV fluoroquinolone. Add anti-MRSA coverage (vancomycin or linezolid) if MRSA risk factors. Add anti-Pseudomonal β-lactam if Pseudomonas risk
PSI vs CURB-65 — Key Differences
- PSI (PORT score): 20 variables, validated in 51,000+ patients, better at identifying LOW-risk patients for outpatient treatment, recommended by IDSA/ATS 2007/2019
- CURB-65: 5 variables (Confusion, Urea, RR, BP, Age ≥65), simpler bedside tool, better for quick HIGH-risk identification, endorsed by BTS guidelines
- Either tool is acceptable per IDSA/ATS 2019. PSI is more conservative (fewer unnecessary admissions); CURB-65 is faster
Frequently Asked Questions
Related Calculators
⚠ Medical Disclaimer: PSI is a severity prediction tool — not a substitute for clinical judgement. Patients with social factors, inability to maintain oral intake, or clinical instability may require admission regardless of low PSI score. Always apply clinical context alongside the score.