Table 4 Estimation of hazard ratio, β coefficient, and risk score based on a multivariate Cox proportional risk model
|  | HR | β coefficient | P value | Risk score |
|---|---|---|---|---|
Sex | ||||
 Female | 1 | 1 |  | 0 |
 Male | 1.406 (0.85–2.324) | 0.34 | 0.185 | 12 |
Age group, years | ||||
  ≤ 55 | 1 | 1 |  | 0 |
  > 55 | 1.414 (0.973–2.055) | 0.346 | 0.069 | 12 |
Staging | ||||
 III | 1 | 1 | .. | 0 |
 IVA | 1.396 (0.958–2.036) | 0.334 | 0.083 | 12 |
 IVB | 1.793 (1.087–2.958) | 0.584 | 0.022 | 21 |
Smoking | ||||
 No | 1 | 1 |  | 0 |
 Yes | 1.150 (0.792–1.670) | 0.14 | 0.463 | 5 |
EBV-DNA levels | ||||
  ≤ 1500 | 1 | 1 |  | 0 |
  > 1500 | 1.848 (1.297–2.633) | 0.614 | 0.001 | 22 |