Table 2.
Univariable and Multivariable Analyses of 90-Day Complications for Instrumented and Noninstrumented Matched Cohorts (Controlled for Age, Sex, and Elixhauser Comorbidity Index)
| Factor or Variable | Univariate Analysis | Multivariate Analysis | |||
| Instrumented Fusion (n = 19,374) | NonInstrumented Fusion (n = 4850) | P Valuea | Odds Ratio (95% CI) | P Valuea | |
| Any adverse events | 2127 (11.0%) | 579 (11.9%) | 0.061 | 1.10 (1.00-1.21) | 0.056 |
| Severe adverse events | 938 (4.8%) | 278 (5.7%) | 0.012 | 1.20 (1.04-1.38) | 0.010 |
| Cardiac arrest | 11 (0.1%) | <10 (0.2%) | 1 | 1.09 (0.30-3.92) | 0.892 |
| Myocardial infarction | 122 (0.6%) | 28 (0.6%) | 0.754 | 0.92 (0.61-1.39) | 0.686 |
| Pulmonary embolism | 159 (0.8%) | 39 (0.8%) | 0.980 | 0.98 (0.69-1.40) | 0.920 |
| Sepsis | 196 (1.0%) | 58 (1.2%) | 0.295 | 1.19 (0.88 - 1.59) | 0.254 |
| Deep vein thrombosis | 271 (1.4%) | 73 (1.5%) | 0.623 | 1.08 (0.83-1.40) | 0.563 |
| Surgical site infection | 372 (1.9%) | 136 (2.8%) | <0.001 | 1.48 (1.21-1.80) | <0.001 |
| Minor adverse events | 1601 (8.3%) | 418 (8.6%) | 0.441 | 1.05 (0.94-1.17) | 0.423 |
| Pneumonia | 264 (1.4%) | 70 (1.4%) | 0.717 | 1.06 (0.82-1.39) | 0.653 |
| Urinary tract infection | 846 (4.4%) | 213 (4.4%) | 0.970 | 1.00 (0.86-1.17) | 0.963 |
| Acute kidney injury | 366 (1.9%) | 105 (2.2%) | 0.236 | 1.14 (0.92-1.42) | 0.240 |
| Wound dehiscence | 229 (1.2%) | 67 (1.4%) | 0.290 | 1.17 (0.89-1.54) | 0.251 |
| Hematoma | 120 (0.6%) | 26 (0.5%) | 0.571 | 0.87 (0.57-1.33) | 0.510 |
| Transfusion | 99 (0.5%) | 34 (0.7%) | 0.135 | 1.38 (0.93-2.04) | 0.108 |
CI = confidence interval
a
Bonferroni correction was used to account for multiple comparisons. The adjusted significance threshold is P ≤ 0.003, and bolded values indicate statistical significance at this level.
Multivariable odds ratio computed with instrumented group as reference group.