Rochester Criteria Calculator - Low-Risk Febrile Infants (0-60 Days)

Rochester Criteria Calculator

Identifies Low-Risk Febrile Infants for Serious Bacterial Infection

Age: 0-60 Days

⚠️ Clinical Context Required: This tool aids clinical decision-making but does not replace clinical judgment. All febrile neonates ≤28 days should be considered high-risk. Close follow-up is essential for all discharged infants.

Initial Requirements

Fever Present: Rectal temperature ≥38.0°C (100.4°F) documented in ED or by parent

Age ≤60 Days: Infant is 60 days old or younger

Low-Risk Criteria (All Must Be Present)

Infant appears well (not toxic, lethargic, or ill-appearing)

Previously healthy infant

• Born at ≥37 weeks gestation
• No perinatal antibiotics
• No prior hospitalization
• No chronic illness
• Not hospitalized longer than mother
• No treatment for unexplained hyperbilirubinemia

No focal infection on physical examination

No evidence of skin, soft tissue, bone, joint, or ear infection

WBC count: 5,000-15,000 cells/μL

Absolute band count: ≤1,500 cells/μL

Urine microscopy: ≤10 WBC/HPF (high power field)

On microscopic examination of spun urine sediment

Stool microscopy (if diarrhea): ≤5 WBC/HPF

📋 How to Use This Tool

Step-by-Step Instructions:

1. Verify fever: Confirm documented temperature ≥38.0°C (100.4°F)
2. Check age: Tool applies only to infants ≤60 days old
3. Assess criteria: Work through each criterion systematically
4. Check boxes: Select only those criteria that are clearly met
5. Calculate: Click "Calculate Risk" to see results
6. Clinical judgment: Use results to guide, not replace, clinical decisions

Advantages (Pros):

• High negative predictive value (98.9%) for serious bacterial infection
• Well-validated in multiple studies since 1994
• Does not require lumbar puncture for initial risk stratification
• Identifies low-risk infants who may avoid hospitalization
• Reduces unnecessary antibiotic use in truly low-risk infants
• Simple, objective criteria that are readily available

Limitations (Cons):

• Sensitivity of ~81-92% means some infants with invasive bacterial infection may be classified as low-risk
• Can miss approximately 7-8% of invasive bacterial infections
• Less sensitive for neonates ≤28 days (missed 2 cases of meningitis in studies)
• Lower specificity (59.8%) compared to modified Philadelphia criteria
• Requires complete laboratory workup (blood count, urinalysis)
• Does not include newer biomarkers (procalcitonin, CRP)
• Performance varies by pathogen and type of infection
• All low-risk infants still require close follow-up

⚠️ Important Considerations:

• All neonates ≤28 days should generally be considered high-risk
• Low-risk classification does NOT mean zero risk
• Close follow-up within 24 hours is mandatory for discharged infants
• Newer criteria (PECARN, Step-by-Step) may offer improved performance

📖 About the Rochester Criteria

Background & Development:

The Rochester Criteria were developed and validated in the 1990s at the University of Rochester to identify febrile infants at low risk for serious bacterial infection (SBI). The original validation study included 1,005 febrile infants ≤60 days old, with 511 meeting all low-risk criteria.

Clinical Performance:

• Sensitivity: 81.5-92.7% for invasive bacterial infections
• Specificity: 59.8% (higher than Philadelphia criteria)
• Negative Predictive Value: 98.9% (95% CI: 97.2-99.6%)
• SBI Rate in Low-Risk Group: 1.0% (5/511 infants)
• SBI Rate in High-Risk Group: 12.3% (61/494 infants)

What is Serious Bacterial Infection (SBI)?

SBI includes bacteremia (bacteria in bloodstream), bacterial meningitis, urinary tract infection (UTI), bacterial pneumonia, and other invasive bacterial infections requiring hospitalization and/or parenteral antibiotics.

Recent Evidence (2018-2024):

• Large multi-center studies confirm ongoing validity
• Performs well in infants 29-60 days old (sensitivity 94.1%)
• Less sensitive in neonates ≤28 days (sensitivity 91.7%)
• Missed 1 case of meningitis in neonates in validation studies
• Enhanced urinalysis improves performance
• Should be used with clinical judgment, not as standalone tool

Clinical Application:

Infants meeting ALL low-risk criteria may be candidates for outpatient management without empiric antibiotics, but require:

• Close follow-up within 24 hours
• Reliable caregivers with access to care
• Clear return precautions
• Review of culture results
• Consideration of local antimicrobial resistance patterns

Alternative/Complementary Criteria:

Other validated approaches include the Philadelphia criteria, Boston criteria, PECARN rule, and Step-by-Step approach. Recent guidelines increasingly incorporate biomarkers like procalcitonin and CRP for enhanced risk stratification.

⚠️ Critical Reminders:

• Tool aids but does not replace clinical judgment
• Local institutional protocols may differ
• Consider repeat evaluation if clinical status changes
• When in doubt, err on the side of caution
• Document decision-making thoroughly

References:

Jaskiewicz JA, et al. Pediatrics. 1994;94(3):390-396. (Original validation study)
Aronson PL, et al. Pediatr Emerg Care. 2019;35(1):22-27. (Recent validation)
Aronson PL, et al. Pediatrics. 2018;142(6):e20181879. (Comparison with Philadelphia criteria)