The management of patients with suspected appendicitis is highly variable with implications for the rate of diagnostic errors, unnecessary admissions and resource consumption. We hypothesise that a structured management algorithm based on the Appendicitis Inflammatory Response (AIR) score can improve diagnostic accuracy, limit the use of diagnostic imaging, and reduce the number of hospital admissions for patients with suspected appendicitis.
Prospective interventional multicentre study. Patients at 25 Swedish hospitals over the age of five, presenting with suspected appendicitis at the emergency department were considered for inclusion. After an initial period of routine management and registration of the AIR score parameters (baseline period), an AIR-score-based management algorithm was implemented (intervention period). The study analyses the discriminating capacity and predictive value of the AIR score and the impact of implementing the AIR-score-based algorithm.
In total, 3791 patients were included. Advanced appendicitis is unlikely at an AIR score <5 points (sensitivity 0.96), and appendicitis is likely at an AIR score >8 (specificity 0.98). The implementation of the AIR-score-based algorithm resulted in fewer negative explorations and operations for phlegmonous appendicitis (1.6% vs 3.4%, p=0.019 and 5.5% vs 9.4%, p=0.003, respectively), a reduction in admissions to hospital and use of imaging (29.5% vs 42.8%, p<0.001 and 19.2% vs 34.5%, respectively), and no difference with regard to advanced appendicitis in the low-risk group, and a decrease in the use of diagnostic imaging in the high-risk group (38.5% vs 53.1%, p=0.021).
The AIR score has high discriminating capacity. Implementing an AIR-score-based algorithm increased diagnostic accuracy and lowered the use of diagnostic imaging and in-hospital observation.