Association between ambulance dispatch priority and patient condition.

Area of Science:

• Emergency medical services research
• Public health surveillance
• Pre-hospital care systems

Background:

• The Medical Priority Dispatch System (MPDS) categorizes emergency calls to determine dispatch priority.
• Accurate matching of dispatch priority to patient condition is crucial for effective emergency medical services (EMS).
• Under-triage and over-triage can lead to delayed or inappropriate responses.

Purpose of the Study:

• To evaluate the accuracy of MPDS chief complaints by comparing dispatch priority with actual patient condition.
• To identify specific chief complaints with significant discrepancies between assigned priority and clinical urgency.
• To provide data for improving the performance of ambulance dispatch systems.

Main Methods:

• Retrospective analysis of emergency ambulance dispatches in Perth, Western Australia (2014-2015).
• Categorization of dispatch priority (Priority 1 vs. Priority 2/3) and patient condition (time-critical vs. less time-critical).
• Statistical comparison using chi-squared tests to calculate false omission rates and positive predictive values for chief complaints.

Main Results:

• Analysis of over 211,000 dispatches revealed variations in accuracy across chief complaints.
• Convulsions/seizures and breathing problems showed higher false omission rates (under-triage) than average.
• Chest pain, heart problems, unknown problem/collapse, and headache showed lower positive predictive values (over-triage) than average.

Conclusions:

• The effectiveness of the MPDS in matching dispatch priority to patient condition varies by chief complaint.
• Specific complaints, such as convulsions/seizures, breathing problems, chest pain, and headache, require further investigation for potential protocol refinement.
• Optimizing dispatch protocols for these identified chief complaints could reduce under-triage and over-triage, enhancing EMS response.