What does the pneumonia severity index predict in CAP?

• A. Predicts morbidity and mortality and the need of hospitalization in CAP
• B. Predicts antibiotic resistance
• C. Predicts the exact length of hospital stay
• D. Predicts likelihood of pleural effusion

Answer: (A)

The Pneumonia Severity Index is designed to estimate a patient’s risk of adverse outcomes from community-acquired pneumonia and to guide disposition decisions. It combines factors such as age, comorbidities, vital signs, mental status, and select laboratory and radiographic findings to stratify patients into risk classes. Higher scores indicate greater risk of death and a stronger indication for hospital admission, while lower scores support outpatient management.

It does not predict antibiotic resistance, an exact length of hospital stay, or the likelihood of a pleural effusion. Those outcomes depend on different factors and aren’t what the PSI was designed to measure.