Objective: To determine the impact of increasing trauma center experience over time on survival and resource utilization.
Methods: The authors studied a retrospective cohort at a single level I trauma center over a 10-year period, from 1986 to 1995. Patients included all hospital admissions and emergency department deaths. The main outcome measures were the case-fatality rate adjusted for injury severity, hospital length of stay, and costs.
Results: A total of 25,979 patients were admitted or died. The number of patients per year increased, from 2063 in 1986 to 3313 in 1995. The proportion of patients transferred from another institution increased from 16.2% to 34.4%. Although mean length of stay declined by 28.4%, from 9.5 to 6.8 days, costs increased by 16.7%, from $14,174 to $16,547. The use of specific radiologic investigations increased; the frequency of operative procedures either remained unchanged (craniotomy, fracture fixation) or decreased (celiotomy). After adjusting for injury severity and demographic factors, the mortality rate decreased over 10 years. The improvement in survival was confined to patients with an injury severity score > or =16.
Conclusion: Over a 10-year period, the case-fatality rate declined in patients with severe injuries. Overall acute care costs increased, partially because of the increased use of radiologic investigations. Even in otherwise established trauma centers, increasing cumulative experience results in improved survival rates in the most severely injured patients. These data suggest that experience contributes to a decrease in mortality rate after severe trauma and that developing trauma systems should consider this factor and limit the number of designated centers to maximize cumulative experience at individual centers.