Table 2.
Uni- and multivariate analysis of factors associated with overall survival
| Univariate analysis | Multivariate analysis | |||||
|---|---|---|---|---|---|---|
| 95% CI | 95% CI | |||||
| Characteristic | HR | Lower | Upper | HR | Lower | Upper |
| Age | 1.033 | 1.032 | 1.035 | 1.022 | 1.02 | 1.024 |
| Great circle distance per 10 miles | 0.999 | 0.997 | 1.00 | 0.998 | 0.996 | 1.00 |
| Sex | ||||||
| Male | Ref | – | – | Ref | – | – |
| Female | 1.037 | 1.00 | 1.077 | 0.873 | 0.836 | 0.912 |
| Race | ||||||
| White | Ref | – | – | Ref | – | – |
| Black | 1.44 | 1.363 | 1.521 | 1.06 | 0.994 | 1.131 |
| Other | 0.965 | 0.869 | 1.07 | 0.9 | 0.801 | 1.011 |
| Median household income | ||||||
| <$40 227 | 1.59 | 1.516 | 1.669 | 1.196 | 1.130 | 1.266 |
| $40 227–50 353 | 1.412 | 1.347 | 1.48 | 1.157 | 1.097 | 1.220 |
| $50 354–63 332 | 1.264 | 1.204 | 1.327 | 1.128 | 1.068 | 1.191 |
| ≥$63 333 | Ref | – | – | Ref | – | – |
| Percent with no high school degree | ||||||
| ≥17.6 | 1.557 | 1.478 | 1.641 | – | – | – |
| 10.9–17.5 | 1.367 | 1.3 | 1.438 | – | – | – |
| 6.3-10.8 | 1.235 | 1.174 | 1.3 | – | – | – |
| <6.3 | Ref | – | – | – | – | – |
| Insurance | ||||||
| Not insured | 0.781 | 0.726 | 0.84 | 0.981 | 0.903 | 1.065 |
| Private insurance | 0.429 | 0.413 | 0.445 | 0.708 | 0.675 | 0.743 |
| Public insurance | Ref | Ref | ||||
| Urban status | ||||||
| Nonmetropolitan | Ref | – | – | – | – | – |
| Metropolitan | 0.897 | 0.86 | 0.935 | – | – | – |
| Facility type | ||||||
| Community | Ref | – | – | – | – | – |
| Comprehensive Community | 0.905 | 0.83 | 0.988 | – | – | – |
| Academic/research | 0.925 | 0.851 | 1.006 | – | – | – |
| I ntegrated network | 0.922 | 0.836 | 1.018 | – | – | – |
| Charlson-Deyo score | ||||||
| 0 | Ref | – | – | Ref | – | – |
| 1 | 1.498 | 1.439 | 1.56 | 1.2135 | 1.161 | 1.272 |
| 2 | 1.953 | 1.824 | 2.092 | 1.485 | 1.375 | 1.603 |
| 3+ | 2.311 | 2.084 | 2.563 | 1.674 | 1.492 | 1.878 |
| Surgical margins | ||||||
| Negative | Ref | – | – | Ref | – | – |
| Positive | 1.39 | 1.33 | 1.452 | 1.414 | 1.346 | 1.486 |
| TNM pathologic stage | ||||||
| 1 | Ref | – | – | Ref | – | – |
| 2 | 1.432 | 1.317 | 1.557 | 1.469 | 1.345 | 1.604 |
| 3 | 1.614 | 1.496 | 1.741 | 2.148 | 1.977 | 2.333 |
| 4 | 2.388 | 2.243 | 2.543 | 3.15 | 2.929 | 3.388 |
| Adjuvant treatment | ||||||
| no adjuvant treatment | Ref | – | – | Ref | – | – |
| Adjuvant radiation | 1.058 | 1.014 | 1.103 | 0.776 | 0.738 | 0.816 |
| Adjuvant chemoradiation | 1.037 | 0.996 | 1.079 | 0.9 | 0.854 | 0.949 |
| Primary sites | ||||||
| Oral cavity | Ref | – | – | Ref | – | – |
| Oropharynx | 0.406 | 0.386 | 0.427 | 0.368 | 0.347 | 0.39 |
| Larynx | 1.128 | 1.084 | 1.174 | 0.854 | 0.814 | 0.896 |
| Hypopharynx | 1.834 | 1.667 | 2.018 | 1.201 | 1.08 | 1.336 |
| TTS (days) | ||||||
| 1-67 | Ref | Ref | – | Ref | – | – |
| 67+ | 1.371 | 1.302 | 1.444 | 1.189 | 1.122 | 1.261 |
HR hazard ratio, CI confidence interval, TNM tumor-node-metastasis, TTS time to surgery