HOSP_TRAUMA indicates the trauma level of the hospital and is based on information from the Trauma Information Exchange Program database (TIEP), a national inventory of trauma centers in the U.S. Information is collected by the American Trauma Society and the Johns Hopkins Center for Injury Research and Policy and funded by the Centers for Disease Control and Prevention ^1,2. The TIEP database is updated quarterly and identifies all U.S. hospitals that are designated as trauma centers by a State or regional authority or verified by the American College of Surgeons' Committee on Trauma (ACS/COT). Designation of trauma center levels I, II, and III are based on criteria developed by the ACS/COT. Level I and II centers have comprehensive resources and are able to care for the most severely injured. Level I centers also provide leadership in education and research. Level III centers provide prompt assessment and resuscitation, emergency surgery and, if needed, transfer to a level I or II center. Level IV and V centers are State-defined and often located in remote areas. These centers resuscitate and stabilize patients and arrange transfer to an appropriate trauma facility. For the NEDS, facilities with levels I, II and III were identified as a trauma center. Level IV and V centers are State-defined and often located in remote areas. These centers resuscitate and stabilize patients and arrange transfer to an appropriate trauma facility. For the NEDS, facilities with levels I, II and III were identified as a trauma center. Level IV and V centers were set aside within the context of these data because many states choose not to designate hospitals at these levels of trauma care and their institutional characteristics have many similarities to community (non-trauma) hospitals in other areas. It is also important to note that while all level I, II, and III trauma centers offer a high level of trauma care, that there may be differences in the services and resources offered by hospitals of different levels. Further, hospitals of different levels may be utilized in diverse ways within the context of individual state trauma systems or the geographic areas in which they operate.

Starting with the 2006 NEDS, trauma centers that are level I, II, and III are distinguished (HOSP_TRAUMA=1, 2, or 3), when possible. To ensure hospital confidentiality, stratum with less than two trauma hospitals were collapsed. In the 2006-2010 NEDS, a collapsed stratification of levels I and II (HOSP_TRAUMA=8) or levels I, II, and III (HOSP_TRAUMA=9) was employed. Beginning with the 2011 NEDS, this collapsing strategy was revised to combine level I with level II (HOSP_TRAUMA=8) and to combine level III with nontrauma (HOSP_TRAUMA=4). This change was prompted by differences between injury-related services provided by trauma level I and II centers versus injury-related services provided by trauma level III centers and nontrauma hospitals. The grouping of trauma hospitals limits analyses performed on trauma hospitals.

Prior to 2007, information on level III trauma centers in Wisconsin was not available in the TIEP data. This caused the under counting of level III trauma centers in the NEDS for the Midwest. Beginning with the 2007 NEDS, level III trauma centers are reported for all states in the Midwest.

¹MacKenzie EJ, Hoyt DB, Sacra JC, et al. National inventory of hospital trauma centers. JAMA. 2003;289:1515-1522.
²American Trauma Society. Trauma Information Exchange Program. Available at: http://www.amtrauma.org/?page=TIEP. Accessed April 2005.