Incentive-Compatible Prehospital Triage in Emergency Medical Services

Abstract

The Emergency Medical Services (EMS) system is designed to handle life-threatening emergencies, but a large and growing number of non-emergency patients are accessing hospital-based healthcare through EMS. A national survey estimated that 17% of ambulance trips to hospital Emergency Departments (EDs) were medically unnecessary, and that these unnecessary trips make up an increasing proportion of all EMS trips. These non-emergency patients are a controllable arrival stream that can be re-directed to an appropriate care provider, reducing congestion in EDs, reducing costs to patients and healthcare payers, and improving patient health, but prehospital triage to identify these patients is almost never implemented by EMS providers in the United States. Using a decision model, we show that prehospital triage is unlikely to occur under the current structure of fee-for-service reimbursements, regardless of how effective the triage process might be, unless low-acuity patients are unprofitable and a hospital is willing to coordinate with EMS. We demonstrate several mechanisms a payer such as Medicare could use to promote prehospital triage: reforming fee-for-service reimbursements or offering a value-based payment, such as bundled payments or shared savings contracts. Using data from a national survey and levels of triage effectiveness demonstrated in the literature, we conservatively estimate that Medicare alone could save between $3 and $70 million per year (depending on triage effectiveness) by providing incentives for prehospital triage. Between 26,500 and 628,000 non-emergency patients could be diverted to more appropriate care options, making prehospital triage a practical step to address hospital emergency department crowding.