Table 2. Multivariable Linear Regression Analysis of Ground Transport Time From Newly Designated Trauma Centers to Existing Trauma Centersa.
| Trauma center variable | Coefficient (SE) | P value |
|---|---|---|
| Trauma centers of any category | ||
| Intercept | 8.05 (3.12) | .01 |
| State designated trauma level I-II (vs III-V)b | 4.57 (2.19) | <.001 |
| Injury-related death rate (deaths/100 000) | 0.17 (0.03) | <.001 |
| For-profit status (vs not-for-profit) | −7.27 (1.89) | <.001 |
| Trauma centers of the same category | ||
| Intercept | 9.02 (3.39) | .008 |
| State designated trauma level I-II (vs III-V)b | 2.76 (0.89) | .07 |
| Injury-related death rate (deaths/100 000) | 0.17 (0.03) | <.001 |
| For-profit status (vs not-for-profit) | −5.98 (2.09) | .005 |
a
Distance to existing trauma centers was assessed as ground transportation time in minutes. A geospatial analysis tool (ArcGIS version 10.8.2; ESRI) computed ground transport times between each trauma center newly designated between 2014 and 2018 and the nearest existing trauma center (by ground transport time) designated prior to 2014.
b
State designated trauma level was treated as a categorical variable (I-II [with highest capacity] and III-V [with limited capacity]).