What is the role of the Bosnick score in diagnosing and managing appendicitis?

The Bosniak Score Does Not Exist for Appendicitis Diagnosis

You are likely referring to the Bonadio scoring system, which is a pediatric-specific tool for predicting perforation risk in children with acute appendicitis, not for diagnosing appendicitis itself. This score should not be confused with diagnostic scoring systems like the Pediatric Appendicitis Score (PAS), Alvarado score, or AIR score 1.

What the Bonadio System Actually Measures

The Bonadio preoperative clinical scoring system predicts perforation risk in pediatric patients already diagnosed with appendicitis, using three variables 1:

• Duration of symptoms >1 day
• Fever >38.0°C
• WBC absolute count >13,000/mm³

The system demonstrates a multivariate ROC curve of 89% for perforation (P < 0.001), with perforation risk increasing linearly from 7% when no variables are present to 85% when all three variables are present 1.

Critical Distinction: Diagnosis vs. Perforation Prediction

The Bonadio system is NOT recommended for diagnosing appendicitis—it predicts complications in children who already have confirmed or highly suspected appendicitis 1. For actual diagnosis, current guidelines strongly recommend different tools.

Recommended Diagnostic Approaches Instead

For Pediatric Patients

Clinical scores alone should NOT be used to diagnose appendicitis in children 1. The 2020 WSES Jerusalem Guidelines explicitly recommend against making diagnosis based on clinical scores alone (QoE: Low; Strength: Weak 2C) 1.

The preferred diagnostic scoring systems for pediatric appendicitis are 1:

• Pediatric Appendicitis Score (PAS): Includes 8 variables with sensitivity of 100%, specificity of 92%, PPV of 96%, and NPV of 99% 2
• AIR score: Outperforms both Alvarado and PAS in children, with the highest discriminating power 1
• Alvarado score: Useful for exclusion but over-diagnoses by 32% 1

For Adult Patients

The AIR score and Adult Appendicitis Score (AAS) are the best performing clinical prediction scores (QoE: High; Strength: Strong 1A) 1. These scores:

• Decrease negative appendectomy rates in low-risk groups 1
• Reduce need for imaging studies and hospital admissions 1
• Have the highest discriminating power in adults 1

Practical Clinical Algorithm

Step 1: Risk Stratification

Use validated diagnostic scores (AIR, AAS in adults; PAS or AIR in children) to stratify patients into low, intermediate, or high risk 1, 3.

Step 2: Imaging Based on Risk

• Low-risk patients: Can be discharged without imaging 3, 4
• Intermediate-risk patients: Proceed to ultrasound as first-line imaging 1, 3
• High-risk patients: Consider CT with IV contrast or surgical consultation 3, 4

Step 3: Use Bonadio System (If Applicable)

Only after appendicitis is diagnosed or highly suspected, apply the Bonadio system in pediatric patients to predict perforation risk and guide urgency of surgical intervention 1.

Common Pitfalls to Avoid

• Do not confuse perforation prediction with diagnosis: The Bonadio system does not diagnose appendicitis 1
• Do not rely on clinical scores alone in children: Always combine with laboratory tests (WBC, CRP) and imaging when indicated 1
• Do not use Alvarado score to confirm appendicitis: It lacks sufficient specificity (QoE: Moderate; Strength: Weak 2B) 1, 4
• Recognize atypical presentations: Preschool-age children often have lower scores and more rapid progression to perforation 1