Table 4.
Univariate and multivariate analysis of predictors of morbidity
| Univariate | Multivariate | ||||
|---|---|---|---|---|---|
|
|
|
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| Morbidity (n=8525) | No morbidity (n=29,888) | P | OR (95% CI) | P | |
| Demographics | |||||
| Mean age (years)±SD | 64 (12) | 60 (13) | <0.001 | 1.011 (1.008-1.013) | <0.001 |
| Obese | 4634 (54.8) | 15,954 (53.6) | 0.055 | 1.065 (1.003-1.132) | 0.041 |
| African American race | 705 (8.8) | 2,378 (8.5) | 0.339 | 1.212 (1.092-1.346) | <0.001 |
| Hispanic ethnicity | 399 (4.9) | 1,651 (5.9) | 0.001 | 0.761 (0.653-0.886) | <0.001 |
| Male gender | 3585 (42.1) | 14,187 (47.5) | <0.001 | 0.949 (0.890-1.012) | 0.114 |
| Comorbidities | |||||
| Smoker | 1393 (16.3) | 6102 (20.4) | <0.001 | 0.921 (0.849-0.998) | 0.046 |
| Dyspnea | 694 (8.1) | 1657 (5.5) | <0.001 | 1.201 (1.074-1.343) | 0.001 |
| Diabetes mellitus | 1879 (22.0) | 5249 (17.6) | <0.001 | 1.048 (0.973-1.129) | 0.217 |
| COPD | 458 (5.4) | 1289 (4.3) | <0.001 | 1.076 (0.941-1.232) | 0.281 |
| Heart failure | 64 (0.8) | 85 (0.3) | <0.001 | 1.017 (0.662-1.565) | 0.937 |
| Hypertension | 5601 (65.7) | 16,944 (56.7) | <0.001 | 1.071 (1.001-1.146) | 0.046 |
| Disseminated cancer | 211 (2.5) | 193 (0.6) | <0.001 | 1.125 (0.864-1.464) | 0.382 |
| Open wound infection | 104 (1.2) | 91 (0.3) | <0.001 | 1.022 (0.693-1.511) | 0.909 |
| Chronic steroid use | 526 (6.2) | 1124 (3.8) | <0.001 | 1.238 (1.089-1.407) | 0.001 |
| Bleeding disorder | 240 (2.8) | 379 (1.3) | <0.001 | 1.516 (1.244-1.846) | <0.001 |
| Preoperative transfusion | 96 (1.1) | 51 (0.2) | <0.001 | 1.455 (0.969-2.185) | 0.070 |
| ASA class ≥3 | 5288 (62.1) | 14,366 (48.1) | <0.001 | 1.182 (1.108-1.261) | <0.001 |
| Lab values, mean±SD | |||||
| Creatinine | 1.0±0.5 | 0.9±0.4 | <0.001 | 1.029 (0.963-1.099) | 0.398 |
| White cell count | 7.4±2.6 | 7.4±2.4 | 0.823 | ||
| Hematocrit | 39.2±5.0 | 41.2±4.2 | <0.001 | 0.938 (0.931-0.944) | <0.001 |
| Platelet | 245±77 | 248±67 | 0.003 | 0.999 (0.999-1.000) | 0.001 |
| Procedural factors | |||||
| Pelvic fixation | 465 (56.8a) | 353 (43.2) | <0.001 | 2.740 (2.307-3.254) | <0.001 |
| Has ALIF | 1628 (19.1) | 8301 (27.8) | <0.001 | 0.644 (0.600-0.692) | <0.001 |
| Has ALIF (PF only) | 78 (16.8) | 81 (22.9) | 0.027 | 0.703 (0.461-1.071) | 0.101 |
| Has CAS | 589 (6.9) | 2095 (7.0) | 0.748 | 0.855 (0.759-0.962) | 0.010 |
| Has CAS (PF only) | 81 (17.4) | 84 (23.8) | 0.024 | 0.640 (.400-1.026) | 0.064 |
| Mean levels fused | 2.6±1.0 | 2.4±0.8 | <0.001 | 1.276 (1.232-1.321) | <0.001 |
| Mean interbody fusions | 1.1±1.2 | 1.2±1.1 | 0.020 | 1.042 (1.012-1.073) | 0.006 |
| Length of stay | 6.4±6.6 | 3.7±3.8 | <0.001 | 1.179 (1.167-1.190) | <0.001 |
aPercent of patients who experienced morbidity within pelvic fixation, #Fisher’s exact test. Bold values indicate significance (P<0.05). ASA: American Society of Anesthesiologists, ALIF: Anterior lumbar interbody fusion, CAS: Computer-assisted surgery, COPD: Chronic obstructive pulmonary disease, SD: Standard deviation, PF: Pelvic fixation