Lower short-term mortality risk. Focus on appropriate antimicrobial therapy and source control.
qPitt Equivalent: Negative
Guidelines & Evidence
Clinical Details
Section 1
When to Use
Clinical Utility
Bedside mortality risk stratification for patients with bloodstream infections (BSIs).
Validating clinical severity in carbapenem-resistant Enterobacteriaceae (CRE) infections (Henderson et al. 2020).
Immediate triage without laboratory results (unlike APACHE or SOFA).
Classification of patients as "Critically Ill" (PBS ≥4) vs "Non-Critically Ill" (PBS <4).
Expanding Use Cases
While originally designed for bacteremia, recent evidence confirms PBS is just as predictive in non-bacteremic infections (Pneumonia, cUTI) caused by multidrug-resistant organisms.
Section 2
Formula & Logic
The 5 Clinical Variables
Mental Status
Normal (0), Disoriented (1), Stupor (2), Coma (4)
Temperature
35.1-36°C or 39-39.9°C (+1) | ≤35°C or ≥40°C (+2)
Hypotension
Drop in SBP >30mmHg, DBP >20mmHg, or Vasopressors (+2)
Mech. Ventilation
Acute requirement for respiratory support (+2)
Cardiac Arrest
Occurring within 48 hours of initial culture (+4)
The qPitt (Quick Pitt)
A binary version (Score 0–5). A qPitt ≥2 provides similar discrimination to a PBS ≥4. It removes the complex temperature weighting and focuses on the high-yield indicators: Hypotension, Mech Vent, Cardiac Arrest, Altered Mental Status, and Hypothermia (<36°C).
Section 3
Pearls/Pitfalls
Resilience vs. Laboratory Scores
The PBS has outperformed more complex scores like APACHE II and CURB-65 because it captures acute physiological failure directly at the bedside. It remains the "crown jewel" of infectious disease stratification after three decades.
The Fever Paradox
While high fever (≥40°C) is included in the classical PBS, hypothermia (<36°C) is actually a stronger independent predictor of early mortality in septic populations.
Section 4
Evidence Appraisal
Key Literature
The Pitt Bacteremia Score Predicts Mortality in Nonbacteremic Infections.
Henderson H et al. • Clin Infect Dis.. 2020;n=475. Validated that a PBS ≥4 predicts mortality with high discrimination (c-statistic 0.85) regardless of culture source.
Resilience of the Pitt Bacteremia Score: 3 Decades and Counting.
Al-Hasan MN et al. • Clin Infect Dis.. 2020;Clinical commentary on the PBS as a unmatched matching and stratification tool in ID research.
Combination antibiotic therapy versus monotherapy for Gram-negative bacteraemia.
Chow JW et al. • Int J Antimicrob Agents.. 1999;The established version of the score weighting used in modern practice.
