Univariate Cox regression analysis for OPP-free survival
| Variable | HR | P Value | 95% CI | Comment |
|---|---|---|---|---|
| Age | 1.16 | .01 | 1.03–1.30 | Continuous |
| Radiation dose | 0.86 | .1 | 0.72–1.03 | Continuous |
| Tumor radiosensitivity | 0.70 | .7 | 0.12–4.17 | Radiosensitive vs -resistant |
| Location | 0.75 | .8 | 0.13–4.48 | T-spine vs C/L-spine |
| Fraction | – | – | – | Collinearity (all OPP occurred in single-fraction regimens) |
Note:—HR indicates hazard ratio; C/L, cervical/lumbar; –, not applicable.