Clinical and economic impact of a hybrid triage strategy (Alvarado Score-Guided CT) for suspected appendicitis

Background: Acute appendicitis is among the most common surgical emergencies worldwide. The Alvarado score is a rapid clinical risk stratification tool, but its sole use may result in unnecessary surgery in intermediate-risk patients. Universal CT imaging, while highly accurate, incurs high costs and radiation exposure. A hybrid triage strategy using the Alvarado score to guide CT decisions may provide optimal diagnostic accuracy while controlling costs.
Objective: To assess clinical and economic results of a hybrid triage protocol using an Alvarado score for suspected appendicitis.
Methods: A retrospective cohort study was conducted at Queen Alia Military Hospital, Jordan from January 2019 to January 2025. Medical records of 500 patients with suspected appendicitis were reviewed. Patients were divided into three groups: Group A (Alvarado ≥8; direct to surgery, n=200), Group B (Alvarado 5–7; CT-guided, n=150), and Group C (universal CT, n=150). Primary outcome was negative appendectomy rate. Cost-effectiveness analysis calculated the incremental cost-effectiveness ratio (ICER) per correctly diagnosed case.
Results: The overall negative appendectomy rate was 9.6% (48/500), highest in Group A (14.5%, 29/200), intermediate in Group B (8.0%, 12/150), and lowest in Group C (4.7%, 7/150) (p<0.001). Perforation rates did not differ significantly (p=0.32). The hybrid strategy had 97% sensitivity and 92% specificity, compared with 92% and 85% for Alvarado alone, and 99% and 95% for universal CT. The hybrid approach saved an estimated $1.2 million annually compared to universal CT (ICER: $3,800 vs. $5,200 per correctly diagnosed case). Independent predictors of negative appendectomy included Alvarado score 5–7 (OR=2.8, 95% CI: 1.6–4.9) and female sex (OR=1.9, 95% CI: 1.1–3.4).
Conclusion: An Alvarado score-guided hybrid triage strategy significantly reduces negative appendectomy rates compared to Alvarado alone (8.0% vs. 14.5%), while avoiding the costs of universal CT. It is safe and cost-effective and supports its use as a standard protocol for suspected appendicitis.