The unexpected survivor: survival rates for severely injured patients in a state trauma region

Objective: To analyze survival rates in patients with high ISS scores and low probability of survival at a Level I trauma center and its surrounding hospitals in a regional trauma system. Patient Population and Methods: NY State (NYS) is divided into 8 regions each with at least one designated Regional (Level I) trauma center. This study group consisted of 8100 patients admitted between January 1994 and December 1996 to 23 hospitals comprising a 7 county urban/suburban/rural trauma region adjacent to a major metropolitan area (2629 patients 1994, 2769 patients 1995 and 2701 patients in 1996). There was only one Regional Level I designated trauma center in this region, and two Level 2 (area) centers. The rest of the 20 hospitals were undesignated. Data were collected as part of the NYS Trauma Registry. Severely injured patients were defined in two ways: TRISS(rts) probability of survival less than 0.5 or an ISS greater than 30. Results: There were a total of 254 patients with a TRISS(rts) ps < 0.5 (172/8100= 3%): 140 at the regional level 1 center and 114 at the remaining hospitals. There were 36 survivors at the Level 1 center (36/140 = 26%) versus 18 survivors at the surrounding hospitals (18/114 = 16%) (p=0.07). Expected survival rate for these patient groups based on TRISS(rts) was 28/140 = 20% (Level 1) and 18/114 (16%)(other hospitals). The survival percentage increased at the level 1 center from 1994 through 1996 (17% in 1994 to 39% in 1996; p=0.04), but not at the other hospitals (14% 1994, 16% 1996). Similar results were obtained based on ISS scores. There were a total of 362 patients with an ISS > 30 (259/8100 = 5%): 232 at the Level I center and 130 at the other hospitals. There were 140/232 (60%) survivors at the Level I center: 62/130 (48%) at the area hospitals (p<0.03 Chi Sq). Conclusions: This Regional level 1 trauma center had marked improvement in survival in it's severely injured patients, as opposed to it's surrounding area hospitals. This increase in survival rate has corresponded to an increase in expenditure, manpower, and quality improvement for trauma at this center. Since this study period there have been 3 new designated level 2 area centers in this region. With the increase in committed trauma resources at these institutions it is expected this improvement will also extend to these centers.