Table 2.
Univariate and Multivariable Analyses of Disease-Specific Survival, Stratified by Surgical and Nonsurgical Management
| Characteristic | Univariate | p | Multivariable | p |
|---|---|---|---|---|
| Age at diagnosis | 1.091 (1.080–1.102) | <0.001 | a | <0.001 |
| Sex | ||||
| Male | 1.000 | — | 1.000 | — |
| Female | 0.413 (0.313–0.545) | <0.001 | 0.598 (0.449–0.797) | <0.001 |
| Race/ethnicity | ||||
| White | 1.000 | — | b | |
| Black | 1.162 (0.671–2.012) | 0.593 | ||
| Asian | 1.033 (0.647–1.650) | 0.892 | ||
| Hispanic | 1.388 (0.959–2.009) | 0.082 | ||
| Other | 0.830 (0.206–3.351) | 0.793 | ||
| Marital status | ||||
| Not married | 1.000 | — | 1.000 | — |
| Married | 0.585 (0.447–0.766) | <0.001 | 0.694 (0.523–0.922) | 0.012 |
| Region | ||||
| West | 1.000 | — | b | |
| Midwest | 0.836 (0.508–1.376) | 0.481 | ||
| Southwest | 0.800 (0.450–1.422) | 0.447 | ||
| East | 0.710 (0.527–0.956) | 0.024 | ||
| Size, cm | ||||
| 0–1.0 | 1.000 | — | a | <0.001 |
| 1.1–4.0 | 4.061 (2.766–5.961) | <0.001 | ||
| >4.0 | 24.942 (16.506–37.691) | <0.001 | ||
| T classification | ||||
| T1 | 1.000 | — | b | |
| T2 | 3.614 (2.364–5.525) | <0.001 | ||
| T3 | 7.049 (4.882–10.179) | <0.001 | ||
| T4 | 51.968 (36.235–74.534) | <0.001 | ||
| Radioactive iodine | ||||
| Not given | 1.000 | — | b | |
| Given | 1.268 (0.966–1.664) | 0.087 | ||
| Surgery | ||||
| No | 1.000 | — | 1.000 | — |
| Yes | 0.157 (0.105–0.236) | <0.001 | 0.555 (0.364–0.847) | 0.006 |
a
Age and tumor size were modeled continuously using a restricted cubic spline function with three knots at age 39, 62, 81, and size 2, 11, 35, respectively.
b
Variables dropped from multivariable model through stepwise variable selection.