Table 1b. Multivariable logistic regression model of chemotherapy versus no chemotherapy.
| Covariate | Level | Odds Ratio (95% CI) | P-value |
|---|---|---|---|
| Year of diagnosis | 2001-2005 | 1.54 (1.42-1.66) | <.001 |
| 1996-2000 | 1.34 (1.24-1.46) | <.001 | |
| 1991-1995 | 1.69 (1.55-1.84) | <.001 | |
| 1985-1990 | 1 (Ref) | ||
| Race | Black | 0.88 (0.81-0.95) | 0.002 |
| Other | 0.64 (0.56-0.73) | <.001 | |
| Asian | 1.13 (0.96-1.34) | 0.147 | |
| Hispanic | 0.95 (0.76-1.17) | 0.611 | |
| White | 1 (Ref) | ||
| Gender | Male | 0.94 (0.90-0.98) | 0.005 |
| Female | 1 (Ref) | ||
| Medicare Status Code | Aged | 1.71 (1.56-1.86) | <.001 |
| Others | 1 (Ref) | ||
| Stage | IV | 0.85 (0.81-0.89) | <.001 |
| Others | 1 (Ref) | ||
| Urban/Rural | Urban/Metro | 0.62 (0.57-0.67) | <.001 |
| Less Urban/Rural | 1 (Ref) | ||
| Radiation | Yes | 1.68 (1.60-1.75) | <.001 |
| No | 1 (Ref) | ||
| Age at diagnosis | 0.98 (0.98-0.98) | <.001 |