Table 2. Differences in covariates between early and late surgery groups.
| Variables | Surgery within 24 hours (early surgery) | Surgery after 24 hours (late surgery) | |||||
|---|---|---|---|---|---|---|---|
| Lived (n=703) | Died (n=28) | P value | Lived (n=1,604) | Died (n=44) | P value | ||
| Surgery day 1 | – | – | – | – | – | – | |
| Death | – | – | – | – | – | – | |
| Age (years) (mean ± std) | 52.7±16.5 | 63.2±19.8 | 0.001 | 57.4±14.2 | 70.2±10.2 | <0.001 | |
| Gender, male, n (%) | 565 (80.4) | 20 (71.4) | 0.246 | 1,267 (79.0) | 34 (77.3) | 0.783 | |
| Race, white vs. other, n (%) | 495 (70.4) | 23 (82.1) | 0.305 | 1,058 (66.0) | 34 (77.3) | 0.060 | |
| CCI (mean ± std) | 2.1±1.6 | 3.4±2.0 | 0.001 | 2.6±1.6 | 4.2±1.3 | <0.001 | |
| LOS (days) (mean ± std) | 12.0±12.4 | 14.8±13.8 | 0.247 | 14.2±12.3 | 19.2±19.1 | 0.092 | |
| ISS (AIS ± std) | 19.7±8.6 | 28.3±16.1 | 0.009 | 19.1±8.5 | 25.6±15.5 | 0.007 | |
| ICU (Y/N), n (%) | 600 (85.3) | 27 (96.4) | 0.100 | 1,141 (71.1) | 42 (95.5) | <0.001 | |
| GCS <15, n (%) | 229 (32.6) | 16 (57.1) | 0.007 | 500 (31.2) | 16 (36.4) | 0.464 | |
| ACS level 1 center, n (%) | 457 (65.0) | 18 (64.3) | 0.937 | 1,064 (66.3) | 31 (70.5) | 0.568 | |
| Comorbidities, n (%) | |||||||
| Hypertension | 222 (31.6) | 15 (53.6) | 0.015 | 630 (39.3) | 24 (54.5) | 0.041 | |
| Alcoholism | 89 (12.7) | 2 (7.1) | 0.386 | 279 (17.4) | 3 (6.8) | 0.066 | |
| Diabetes | 85 (12.1) | 8 (28.6) | 0.010 | 287 (17.9) | 15 (34.1) | 0.006 | |
| Respiratory disease | 29 (4.1) | 4 (14.3) | 0.011 | 106 (6.6) | 9 (20.5) | <0.001 | |
| Obesity | 45 (6.4) | 4 (14.3) | 0.102 | 136 (8.5) | 6 (13.6) | 0.229 | |
| CHF | 10 (1.4) | 4 (14.3) | <0.001 | 42 (2.6) | 4 (9.1) | 0.010 | |
| Cardiac disease | 14 (2.0) | 4 (14.3) | <0.001 | 72 (4.5) | 5 (11.4) | 0.033 | |
| Cancer | 3 (0.4) | 0 | 1.000 | 13 (0.8) | 1 (2.3) | 0.297 | |
| Dementia | 11 (1.6) | 0 | 0.505 | 40 (2.5) | 1 (2.3) | 0.926 | |
| Renal disease | 3 (0.4) | 0 | 1.000 | 16 (1.0) | 3 (6.8) | <0.001 | |
| Liver disease | 3 (0.4) | 0 | 0.666 | 9 (0.6) | 0 | 1.000 | |
| PVD | 0 | 0 | – | 9 (0.6) | 0 | 1.000 | |
| Stroke | 15 (2.1) | 1 (3.6) | 0.610 | 38 (2.4) | 4 (9.1) | 0.005 | |
CCI, Charlson comorbidity index; std, standard deviation; LOS, length of stay; ISS, injury severity score; AIS, abbreviated injury score; ICU, intensive care unit; GCS, Glasgow Coma Scale; ACS, acute central cord syndrome; CHF, congestive heart failure; PVD, peripheral vascular disease.