Evaluation of an Acuity Matrix Tool for Critical Care Transport

Determining patient acuity before interfacility transport allows for better use of assets and personnel if it can be done accurately and reliably. We developed an acuity matrix to be used at the time of dispatch and sought to validate it against actual findings upon patient contact and compare dispatcher and flight crew determinations.

Lifeguard is a public, not-for-profit, university-owned, fixed-wing, rotor-wing, and ground transport agency. Lifeguard has its own communications center staffed by paramedics. At the time of call intake, before crew notification, our dispatchers recorded their determination of acuity. After dispatch, but before departure, the flight crew recorded their determination of acuity. After completion of the transport, the flight crew recorded the final determination of acuity. Results were compared using Gwet's agreement coefficient (AC) with quadratic weighting.

The matrix was implemented in April 2023. Between April 2023 and September 2023, there were 825 total dispatches and 674 with complete data. Dispatchers had excellent agreement (89.1%) with the medical crew on initial tier assignment (Gwet's AC, 0.96; 95% confidence interval [CI], 0.94-0.97) with 5.7% overtriage and 5.2% undertriage. Dispatchers also had excellent agreement (85.9%) with final acuity (Gwet's AC, 0.94; 95% CI, 0.93-0.96); they overtriaged 6.7% and undertriaged 7.4%. Medical crew had excellent agreement (92.9%) with final acuity (Gwet's AC, 0.97; 95% CI, 0.96-0.98); they overtriaged 4.3% and undertriaged 2.9%.

Flight crew and paramedic dispatchers can accurately and consistently determine patient acuity based only on dispatch information with outstanding agreement. This tool may have a role in triaging multiple transport requests, assigning the appropriate asset and personnel, determining when it is reasonable to expect crew to stay over time, and conducting utilization review.