Validation of the Appendicitis Inflammatory Response (AIR) Score

Area of Science:

• Emergency Medicine
• Surgical Diagnostics
• Clinical Decision Support

Background:

• Appendicitis diagnosis requires accurate risk stratification due to varying severity.
• The Appendicitis Inflammatory Response (AIR) score is a potential tool for managing suspected appendicitis.
• Prospective validation of the AIR score is crucial for its clinical adoption.

Purpose of the Study:

• To prospectively validate the diagnostic performance of the Appendicitis Inflammatory Response (AIR) score.
• To assess the AIR score's effectiveness in risk stratifying patients with suspected appendicitis.
• To determine the AIR score's utility in identifying complicated appendicitis.

Main Methods:

• Prospective inclusion of 3878 patients aged over five with suspected appendicitis across 25 Swedish emergency departments.
• Estimation of the diagnostic properties of the AIR score.
• Analysis of the AIR score's performance in different patient subgroups and symptom durations.

Main Results:

• The AIR score demonstrated higher accuracy in detecting complicated appendicitis (ROC area 0.89) compared to any appendicitis (ROC area 0.83).
• Performance was superior in patients under 15 years and those with symptom duration >47 hours (ROC area 0.93 for complicated appendicitis).
• A low AIR score (<4) indicated a low likelihood of complicated appendicitis (NPV 99%), while a high score (>8) suggested likely appendicitis (PPV 96% in young patients).

Conclusions:

• The AIR score exhibits high sensitivity for complicated appendicitis.
• It effectively identifies subgroups with low or high probabilities of appendicitis.
• The AIR score is validated as a reliable decision support tool, particularly in children and patients with prolonged symptoms.