Table 2.
Likelihood of Receipt of Adjuvant Chemotherapy Among Patients With Stage III Colon Cancer
| Factor | OR (95% CI) | P |
|---|---|---|
| Travel distance, miles | ||
| 0-12.49 | 1 | |
| 12.5-49.9 | 0.99 (0.92 to 1.06) | .73 |
| 50-249 | 0.87 (0.78 to 0.96) | .009 |
| ≥ 250 | 0.36 (0.28 to 0.45) | < .001 |
| Density level of MO | ||
| High | 1 | |
| Low | 0.98 (0.84 to 1.14) | .77 |
| Age at diagnosis, years | ||
| 18-50 | 1 | |
| 51-64 | 0.75 (0.69 to 0.82) | < .001 |
| 65-70 | 0.50 (0.44 to 0.56) | < .001 |
| 71-75 | 0.35 (0.31 to 0.39) | < .001 |
| 76-80 | 0.20 (0.17 to 0.22) | < .001 |
| Race/ethnicity | ||
| Non-Hispanic white | 1 | |
| Hispanic | 0.94 (0.84 to 1.06) | .32 |
| Black | 0.79 (0.73 to 0.85) | < .001 |
| Other | 0.96 (0.84 to 1.11) | .62 |
| Unknown | 1.10 (0.99 to 1.23) | .07 |
| Sex | ||
| Male | 1 | |
| Female | 1.08 (1.02 to 1.14) | .007 |
| Insurance | ||
| Private | 1 | |
| Uninsured | 0.46 (0.41 to 0.52) | < .001 |
| Medicaid | 0.50 (0.44 to 0.57) | < .001 |
| Medicare (age 18-64 years) | 0.45 (0.40 to 0.51) | < .001 |
| Medicare with supplement | 1.10 (1.00 to 1.22) | .05 |
| Medicare without supplement | 0.76 (0.67 to 0.86) | < .001 |
| Medicare Advantage | 0.98 (0.84 to 1.13) | .75 |
| Medicare/Medicaid | 0.53 (0.45 to 0.63) | < .001 |
| Missing | 0.52 (0.39 to 0.69) | < .001 |
| Diagnosis year | ||
| 2007 | 1 | |
| 2008 | 1.03 (0.96 to 1.12) | .39 |
| 2009 | 0.99 (0.92 to 1.08) | .90 |
| 2010 | 1.00 (0.92 to 1.08) | .92 |
| Median income level | ||
| < $30,000 | 1 | |
| $30,000-$34,999 | 0.99 (0.91 to 1.09) | .91 |
| $35,000-$45,999 | 1.05 (0.96 to 1.15) | .29 |
| ≥ $46,000 | 1.08 (0.99 to 1.19) | .10 |
| Missing | 0.97 (0.77 to 1.23) | .81 |
| Facility type | ||
| Community cancer program | 0.96 (0.87 to 1.05) | .36 |
| Comprehensive community cancer program | 1 | |
| Teaching/research center | 0.92 (0.85 to 1.01) | .08 |
| NCI program/network | 1.32 (1.15 to 1.51) | < .001 |
| Other | 0.98 (0.88 to 1.09) | .73 |
| Charlson-Deyo comorbidity score | ||
| 0 | 1 | |
| 1 | 0.88 (0.82 to 0.94) | < .001 |
| ≥ 2 | 0.59 (0.55 to 0.65) | < .001 |
| No. of positive lymph nodes | ||
| < 4 | 1 | |
| ≥ 4 | 1.21 (1.15 to 1.28) | < .001 |
| Unknown | 1.09 (0.70 to 1.68) | .70 |
| Tumor grade | ||
| Well differentiated | 1 | |
| Moderately differentiated | 1.15 (1.03 to 1.27) | .009 |
| Poorly differentiated | 1.19 (1.06 to 1.34) | .003 |
| Undifferentiated | 1.32 (1.06 to 1.63) | .01 |
| Unknown | 0.94 (0.77 to 1.13) | .50 |
| Surgical margin | ||
| Negative | 1 | |
| Positive | 0.90 (0.82 to 1.00) | .05 |
| Unknown | 1.25 (0.96 to 1.64) | .10 |
| Region | ||
| Northeast | 1 | |
| Midwest | 1.28 (1.16 to 1.42) | < .001 |
| South | 1.03 (0.93 to 1.13) | .58 |
| West | 0.74 (0.66 to 0.83) | < .001 |
Abbreviations: MO, medical oncologist; NCI, National Cancer Institute; OR, odds ratio.