Cost-Effectiveness of Field Trauma Triage among Injured Adults Served by Emergency Medical Services

Abstract

Background: The American College of Surgeons Committee on Trauma sets national targets for the accuracy of field trauma triage at ≥95% sensitivity and ≥65% specificity, yet the cost-effectiveness of realizing these goals is unknown. We evaluated the cost-effectiveness of current field trauma triage practices compared with triage strategies consistent with the national targets.

Study design: This was a cost-effectiveness analysis using data from 79,937 injured adults transported by 48 emergency medical services agencies to 105 trauma and nontrauma hospitals in 6 regions of the western United States from 2006 through 2008. Incremental differences in survival, quality-adjusted life years (QALYs), costs, and the incremental cost-effectiveness ratio (costs per QALY gained) were estimated for each triage strategy during a 1-year and lifetime horizon using a decision analytic Markov model. We considered an incremental cost-effectiveness ratio threshold of <$100,000 to be cost-effective.

Results: For these 6 regions, a high-sensitivity triage strategy consistent with national trauma policy (sensitivity 98.6%, specificity 17.1%) would cost $1,317,333 per QALY gained, and current triage practices (sensitivity 87.2%, specificity 64.0%) cost $88,000 per QALY gained, compared with a moderate sensitivity strategy (sensitivity 71.2%, specificity 66.5%). Refining emergency medical services transport patterns by triage status improved cost-effectiveness. At the trauma-system level, a high-sensitivity triage strategy would save 3.7 additional lives per year at a 1-year cost of $8.78 million, and a moderate sensitivity approach would cost 5.2 additional lives and save $781,616 each year.

Conclusions: A high-sensitivity approach to field triage consistent with national trauma policy is not cost-effective. The most cost-effective approach to field triage appears closely tied to triage specificity and adherence to triage-based emergency medical services transport practices.

Figure 1

Model schematic of current field triage processes versus two alternative triage strategies. Field triage processes do not involve knowledge about injury severity prior to hospital arrival. The decision tree branch integrating injury severity is included to provide the true prevalance of serious injury in the population, providing the ability to test different prevalance values. However, input parameters were adjusted to evaluate field triage as it is actually practiced, with injury severity unknown by emergency medical service providers at the time of triage.

Figure 2

Cost-effectiveness acceptability curves for 3 different field trauma triage strategies among injured adults transported by emergency medical services. The curve shows the probability that a triage strategy is cost-effective across a range of maximum willingness to pay per quality-adjusted life year gained values. The probability is derived from 3,000 rounds of simulation that randomly sampled parameter values from the distributions assigned. The high-sensitivity triage strategy is portrayed at the bottom of the figure along the 0% axis and therefore is not visible. The probability cost effective does not increase from zero for the high sensitivity triage until willingness to pay per quality-adjusted life years is greater than $1,000,000.

Figure 3

The estimated annual impact of 3 approaches to field trauma triage at the trauma system level, estimated at 1-year post-injury. The standard deviation of each estimate is derived from 3,000 rounds of simulation with input parameters sampled from the designated distribution. To generate estimates at the trauma system level, we averaged the total number of injured patients transported by emergency medical services, deaths and costs across the 6 regional trauma systems included in the cohort. We used decision analytic modeling to generate estimates and 95% confidence intervals.