Results of logistic regression model
| Variables | OR (95% CI) | P value |
| All patients | ||
| Year | ||
| 2007–2011 | Reference | |
| 2012 | 0.953 (0.637 to 1.427) | 0.815 |
| 2013 | 0.528 (0.326 to 0.854) | 0.009 |
| 2014 | 0.512 (0.321 to 0.817) | 0.005 |
| 2015 | 0.618 (0.394 to 0.967) | 0.035 |
| 2016 | 0.502 (0.303 to 0.832) | 0.008 |
| Age | 1.006 (1.000 to 1.013) | 0.068 |
| Sex | ||
| Male | Reference | |
| Female | 0.951 (0.721 to 1.253) | 0.720 |
| Site | ||
| Non-NUH | Reference | |
| NUH | 2.945 (2.195 to 3.950) | <0.001 |
| Disease | ||
| Proximal femur fracture | Reference | |
| Traumatic intracranial hemorrhage | 16.361 (9.347 to 28.640) | <0.001 |
| Cardiovascular and lung injury | 44.628 (23.362 to 85.253) | <0.001 |
| Abdominal organ injury | 30.200 (13.561 to 67.255) | <0.001 |
| Pelvic fracture | 3.676 (1.706 to 7.919) | 0.001 |
| Other fracture | 0.144 (0.056 to 0.375) | <0.001 |
| Severe multiple trauma | 180.940 (96.494 to 339.286) | <0.001 |
| Spinal cord injury | 6.181 (2.593 to 14.732) | <0.001 |
| Time from emergencycall toarriveat hospital | 0.997 (0.990 to 1.005) | 0.505 |
| *Subgroup analyses | ||
| Age 15–64 years | ||
| 2007–2011 | Reference | |
| 2012 | 0.963 (0.574 to 1.616) | 0.885 |
| 2013 | 0.408 (0.195 to 0.855) | 0.018 |
| 2014 | 0.539 (0.275 to 1.057) | 0.072 |
| 2015 | 0.946 (0.533 to 1.677) | 0.849 |
| 2016 | 0.643 (0.327 to 1.265) | 0.201 |
| Age >64 years | ||
| 2007–2011 | Reference | |
| 2012 | 0.969 (0.555 to 1.691) | 0.911 |
| 2013 | 0.600 (0.329 to 1.094) | 0.096 |
| 2014 | 0.589 (0.326 to 1.066) | 0.080 |
| 2015 | 0.528 (0.285 to 0.978) | 0.042 |
| 2016 | 0.482 (0.241 to 0.963) | 0.039 |
Each OR refers to mortality.
*For those under 15 years old, we did not analyze because death number was 0 except for 2010.
NUH, transported to Nagasaki University Hospital; non-NUH, transported to non-Nagasaki University Hospital.