Table 4.
Multivariable Cox proportional hazards models for overall survival in patients receiving treatment for rectal adenocarcinoma incorporating propensity score (Cox model with propensity score)
| Significant characteristic | Hazard of death (95% CI) | p-value |
|---|---|---|
| Sex | ||
| Male | Ref | |
| Female | 0.83 (0.79–0.88) | <0.0001 |
| Distance (miles) | ||
| ≤11 | Ref | |
| >11 | 0.93 (0.87–0.98) | 0.008 |
| Comorbidity score | ||
| 0 | Ref | |
| 1 | 1.30 (1.22–1.39) | <0.0001 |
| ≥2 | 1.91 (1.71–2.13) | <0.0001 |
| Radiation technique | ||
| Non-IMRT | Ref | |
| IMRT | 1.13 (1.05–1.22) | 0.0022 |
| Insurance | ||
| None | Ref | |
| Private | 0.71 (0.63–0.79) | <0.0001 |
| Government | 1.32 (1.17–1.47) | <0.0001 |
| Grade | ||
| Well differentiated | Ref | |
| Moderately differentiated | 1.01 (0.90–1.12) | 0.92 |
| Poorly differentiated | 1.70 (1.59–1.82) | <0.0001 |
| Facility location | ||
| Metropolitan | Ref | |
| Urban | 1.12 (1.04–1.21) | 0.0031 |
| Rural | 1.18 (1.00–1.39) | 0.049 |
| Race | ||
| White | Ref | |
| African-American | 1.15 (1.04–1.26) | 0.0056 |
| Other | 0.91 (0.80–1.04) | 0.15 |
IMRT, intensity-modulated radiation therapy; CI, confidence interval.