Candidate for the Lee B. Lusted Student Prize Competition
Purpose: Trauma centers (TC) reduce mortality by 25% for severely injured patients but cost significantly more than non-trauma centers (NTC). The CDC’s 2009 prehospital emergency medical services (EMS) guidelines seek to reduce undertriage of these patients to NTC to <5% and reduce overtriage of minor injury patients to TC to <25%. We assessed the cost-effectiveness of improving prehospital trauma triage in U.S. regions with <1 hour EMS access to TCs (84% of the population).
Method: We developed a decision-analytic Markov model to evaluate improvements in prehospital trauma triage given a baseline undertriage rate of major injury patients to NTC of 20% and overtriage rate of minor trauma patients to TC of 50%. The model follows patients from injury through prehospital care, hospitalization, first year post-discharge, and the remainder of life. Patients are trauma victims with a mean age of 43 (range: 18-85) with Abbreviated Injury Scores (AIS) from 1-6. Cost and outcomes data were derived from the National Study on the Costs and Outcomes of Trauma for patients with moderate to severe injury (AIS 3-6), National Trauma Data Bank, and published literature for patients with minor injury (AIS 1-2). Outcomes included costs (2009$), quality adjusted life-years (QALY), and incremental cost-effectiveness ratios.
Result: Reducing undertriage rates from 20% to 5% would yield 3.9 QALYs gained per 100 patients transported by EMS. Reducing overtriage rates from 50% to 25% would save $108,000 per 100 patients transported. Reducing both undertriage to 5% and overtriage to 25% would be cost-effective at $13,300/QALY gained and yield 3.9 QALYS per 100 patients. One could spend $196,000 per 100 patients transported to reduce undertriage to 5% and overtriage to 45% and still achieve an incremental cost-effectiveness ratio below $50,000/QALY. Results were somewhat sensitive to scenarios in which severely injured patients benefited less than expected from treatment at a TC relative to at a NTC or the cost difference of treating patients with minor injures at TCs and NTCs were smaller than expected.
Conclusion: Reducing prehospital undertriage of trauma patients is cost-effective and reducing overtriage of minor injury patients is cost-saving provided patients with minor injuries do not suffer worse outcomes from treatment at NTCs. With approximately 4.5 million annual EMS trauma transports, reducing overtriage by 25% could save up to $4.8 billion/year.