Comparison of ambulance dispatch protocols for nontraumatic abdominal pain

Area of Science:

• Emergency medicine
• Health services research

Background:

• Nontraumatic abdominal pain is a common reason for emergency medical services (EMS) activation.
• Ambulance dispatch protocols aim to efficiently allocate resources while ensuring patient safety.
• Evaluating the accuracy and cost-effectiveness of different dispatch protocols is crucial for optimizing EMS operations.

Purpose of the Study:

• To compare undertriage and overtriage rates for six ambulance dispatch protocols for nontraumatic abdominal pain.
• To identify the optimal and most cost-effective protocol for dispatching ambulances for this patient group.

Main Methods:

• Retrospective chart review of 902 patients presenting with nontraumatic abdominal pain.
• Development and comparison of six ambulance dispatch protocols (indiscriminate, four selective, no-dispatch).
• Utility and cost-effectiveness analyses, including sensitivity analysis, were performed.

Main Results:

• Only 7.8% of patients with nontraumatic abdominal pain were classified as emergencies.
• Selective protocols showed overtriage rates from 10% to 51% and undertriage rates of 4% to 7%.
• No single protocol was superior based on medical directors' utility values; cost-effectiveness depended on the cost of undertriage errors.

Conclusions:

• The majority of patients with nontraumatic abdominal pain do not have emergency conditions requiring ambulance transport.
• Indiscriminate dispatch is the least expensive protocol if an undertriage error exceeds $3,674.
• No ambulance dispatch is the least expensive strategy if an undertriage error costs less than $3,674.