Trauma system impact on admission site: A comparison of two states

Objective: To introduce a measure assessing statewide hospital admission patterns for trauma and evaluate its utility in identifying significant admission redistributions in neighboring states as a function of trauma system implementation. Methods: A retrospective claims database analysis was performed of hospitalized trauma patients in Washington and Oregon. The site of hospitalization and diagnostic information were used to determine an admission rate difference for each hospital: the rate of index patient admissions minus the rate of non-index patient admissions. Mean admission rate differences for Level II and III versus other hospitals in each state were compared as a function of time. Results: A bias in favor of admitting more serious injuries to Level II and III hospitals was seen with trauma system implementation in both states, but it was more pronounced in the Oregon trauma system. Conclusion: Assessment of admission rate differences is a helpful method of characterizing the evolution of statewide trauma systems.