Development and Validation of an Administrative Claims Measure of Emergency Medical Services (EMS) Triage Quality for...

In general, Medicare pays for emergency ground ambulance services when a patient is transported to the nearest emergency department (ED) or other select facilities. As state and local agencies strive to provide high quality person-centered emergency care in locations outside the ED, there is a need for a reliable and valid prehospital quality measure to ensure patient safety. The Centers for Medicare and Medicaid Innovation Center's Emergency Triage, Treat and Transport (ET3) Model created a unique opportunity to develop a quality measure for ambulance organizations to measure safe and effective prehospital care. Our objective was to develop and validate the Risk Adjusted Post-Ambulance Provider Triage ED Visit Rate Measure.

The measure was developed using 2021-2023 Medicare Part B fee-for-service administrative and claims data from 67 ambulance organizations that participated in the ET3 Model, triaging patients using predetermined clinical protocols. The measure cohort included patients that were either transported to an alternative destination (TAD), such as urgent care, or provided treatment in place (TIP). The measure outcome was met if the patient subsequently had an ED visit or died within three days of a TAD/TIP encounter, as an inverse measure, lower is better. We calculated a risk-adjusted measure score using a hierarchical generalized linear model approach, adjusting for patient-level variables and calculating model and measure performance. Finally, we assessed measure face validity and construct validity. To ensure measure reliability, some results were examined using a minimum case threshold of 20 TAD/TIP encounters by each ambulance organization.

Among the 22 ambulance organizations that met the minimum case volume threshold, the mean, SD measure score was 20.3 (5.3), ranging from 11.6 to 35.4. The mean (SD) reliability signal-to-noise ratio was 0.791 (0.124). Nine of 11 (82%) members of an interested party consensus group provided a positive vote of face validity. Construct validity was demonstrated by identifying an anticipated negative correlation with three relevant prehospital measures.

The Risk Adjusted Post-Ambulance Provider Triage ED Visit Rate Measure is a reliable and valid measure that fills a critical gap in assessing patient safety in prehospital care in the United States.