| Access to trauma care has great impact on health outcomes of patients injured in traffic crashes. This dissertation consists of three essays on issues related to access to level I or II trauma centers and traffic related injury outcomes. In the first essay, using the Wisconsin Crash Outcome Data Evaluation System (CODES) data for an 11-year period from 1992 to 2002, I evaluate the effects of distance to level I or II trauma center on survival. The straight line distances from municipalities where injuries occurred to the nearest level I or II trauma center were calculated using ArcMap software. I find that being injured in locations greater than 10 miles from the nearest level I or II trauma centers has up to a 57% higher risk of death, compared to closer locations, after adjusting for injury severity and other confounding factors. In the second essay, I examine the role of Helicopter Emergency Medical Service (HEMS) in transporting patients directly from injury scenes, compared to Ground Emergency Medical Service (GEMS). Trauma registry data from University of Wisconsin Hospital and Clinics (UWHC) during the years 2000 to 2004 were analyzed. A statistical method, multiple imputation, was implemented to impute missing values in HEMS and GEMS transport time. I find that compared to GEMS, HEMS is associated with a statistically significant 65% mortality reduction in patients transferred directly from the injury scene. In the third essay, I investigate the impact of interfacility transfer on mortality, functional status at hospital discharge and length of hospital stay in patients with traffic related injuries. Analyzing trauma registry data from UWHC, I find that compared to patients transferred directly from the injury scenes, those transferred from other facilities have longer hospital stays and worse functional status at hospital discharge. Mortality is similar in both groups, directly transferred from the scene and interfacility transfers, which is consistent with previous literature and may reflect the fact that this study was not able to include patients who died at the referring hospitals before having an opportunity to be transferred to level I or II trauma care. |
