Table 2.
Univariable analysis of factors associated with overall survival
| Before matching | After matching | |||||
|---|---|---|---|---|---|---|
| Variable | HR | 95 % CI | P-value | HR | 95 % CI | P-value |
| Stage | ||||||
| Stage IIB/C | 2.15 | (2.07, 2.24) | <.0001 | 1.70 | (1.62, 1.78) | <.0001 |
| Stage IIIA | 1.00 | – | – | 1.00 | – | – |
| Age | ||||||
| 18–49 | 1.00 | – | – | 1.00 | – | – |
| 50–64 | 1.30 | (1.17, 1.45) | <.0001 | 1.41 | (1.22, 1.63) | <.0001 |
| 65–74 | 2.23 | (2.02, 2.48) | <.0001 | 2.48 | (2.16, 2.86) | <.0001 |
| 75 and more | 4.86 | (4.41, 5.37) | <.0001 | 5.12 | (4.47, 5.87) | <.0001 |
| Race/ Ethnicity | ||||||
| White | 1.00 | – | – | 1.00 | – | – |
| Black | 0.96 | (0.91, 1.02) | 0.19 | 1.06 | (0.98, 1.14) | 0.14 |
| American Indian, Aleutian, or Eskimo | 0.90 | (0.61, 1.33) | 0.60 | 0.93 | (0.58, 1.47) | 0.75 |
| Asian or Pacific Islander | 0.55 | (0.47, 0.64) | <.0001 | 0.62 | (0.50, 0.75) | <.0001 |
| Other | 0.63 | (0.46, 0.87) | 0.005 | 0.64 | (0.41, 0.99) | 0.05 |
| Facility Type | ||||||
| Community cancer program | 1.39 | (1.31, 1.48) | <.0001 | 1.40 | (1.30, 1.52) | <.0001 |
| Comprehensive community cancer center | 1.21 | (1.16, 1.26) | <.0001 | 1.24 | (1.17, 1.31) | <.0001 |
| Academic research program | 1.00 | – | – | 1.00 | – | – |
| Facility Location | ||||||
| New England | 1.08 | (0.99, 1.18) | 0.10 | 0.94 | (0.84, 1.06) | 0.32 |
| Mid Atlantic | 1.07 | (0.99, 1.16) | 0.07 | 0.98 | (0.89, 1.08) | 0.68 |
| South Atlantic | 1.06 | (0.99, 1.13) | 0.12 | 1.00 | (0.92, 1.09) | 0.98 |
| East North Central | 1.10 | (1.03, 1.18) | 0.008 | 1.04 | (0.95, 1.14) | 0.39 |
| East South Central | 1.09 | (0.998, 1.20) | 0.05 | 1.08 | (0.97, 1.21) | 0.16 |
| West North Central | 1.10 | (1.005, 1.19) | 0.04 | 1.04 | (0.94, 1.16) | 0.43 |
| West South Central | 1.01 | (0.92, 1.11) | 0.80 | 0.99 | (0.89, 1.11) | 0.84 |
| Mountain | 0.93 | (0.83, 1.04) | 0.20 | 0.87 | (0.75, 1.01) | 0.06 |
| Pacific | 1.00 | – | – | 1.00 | – | – |
| Urban/Rural Location | ||||||
| Metro ≥1 million | 1.00 | – | – | 1.00 | – | – |
| Metro 250 k to 1 million | 1.07 | (1.02, 1.12) | 0.008 | 1.09 | (1.03, 1.15) | 0.004 |
| Urban <250 k | 1.07 | (1.004, 1.14) | 0.04 | 1.06 | (0.98, 1.14) | 0.17 |
| Urban ≥ 20 k adjacent metro | 1.10 | (1.002, 1.21) | 0.046 | 1.10 | (0.98, 1.24) | 0.09 |
| Urban ≥ 20 k not adjacent metro | 1.04 | (0.89, 1.22) | 0.65 | 1.05 | (0.87, 1.26) | 0.63 |
| Urban <20 k adjacent metro | 1.13 | (1.04, 1.23) | 0.006 | 1.06 | (0.95, 1.18) | 0.30 |
| Urban <20 k not adjacent metro | 1.23 | (1.10, 1.38) | 0.0005 | 1.32 | (1.15, 1.52) | 0.0001 |
| Rural <2500 adjacent metro | 1.02 | (0.85, 1.24) | 0.81 | 0.88 | (0.68, 1.14) | 0.33 |
| Rural <2500 not adjacent metro | 1.12 | (0.94, 1.33) | 0.21 | 1.06 | (0.85, 1.32) | 0.58 |
| Comorbidities | ||||||
| 0 | 1.00 | – | – | 1.00 | – | – |
| 1 | 1.46 | (1.40, 1.53) | <.0001 | 1.49 | (1.42, 1.58) | <.0001 |
| 2 | 2.29 | (2.16, 2.42) | <.0001 | 2.29 | (2.13, 2.46) | <.0001 |
| Primary Site | ||||||
| Cecum | 1.00 | – | – | 1.00 | – | – |
| Ascending Colon | 0.96 | (0.91, 1.02) | 0.15 | 1.04 | (0.97, 1.11) | 0.30 |
| Hepatic Flexure | 0.97 | (0.88, 1.07) | 0.51 | 0.95 | (0.84, 1.07) | 0.39 |
| Transverse Colon | 1.07 | (0.997, 1.14) | 0.06 | 0.93 | (0.85, 1.02) | 0.11 |
| Splenic Flexure | 1.07 | (0.96, 1.18) | 0.23 | 0.90 | (0.77, 1.04) | 0.15 |
| Descending Colon | 0.85 | (0.78, 0.93) | 0.0003 | 0.85 | (0.77, 0.95) | 0.003 |
| Sigmoid Colon | 0.76 | (0.72, 0.80) | <.0001 | 0.82 | (0.77, 0.87) | <.0001 |
| Overlapping Lesions | 1.19 | (1.03, 1.38) | 0.02 | 0.80 | (0.62, 1.03) | 0.08 |
| Not Otherwise Specified | 1.14 | (1.004, 1.29) | 0.04 | 1.13 | (0.95, 1.33) | 0.17 |
| Grade | ||||||
| Well differentiated | 1.00 | – | – | 1.00 | – | – |
| Moderately differentiated | 1.09 | (1.02, 1.16) | 0.01 | 1.04 | (0.96, 1.13) | 0.37 |
| Poorly differentiated | 1.39 | (1.29, 1.50) | <.0001 | 1.11 | (1.01, 1.22) | 0.03 |
| Undifferentiated, anaplastic | 1.74 | (1.53, 1.97) | <.0001 | 1.23 | (1.02, 1.48) | 0.03 |
| Surgical Margins | ||||||
| No residual tumor | 1.00 | – | – | 1.00 | – | – |
| With Residual tumor | 1.91 | (1.81, 2.02) | <.0001 | 1.24 | (1.03, 1.49) | 0.02 |
| Readmission within 30 days of Surgery | ||||||
| Not readmitted | 1.00 | – | – | 1.00 | – | – |
| Readmitted | 1.15 | (1.08, 1.22) | <.0001 | 1.13 | (1.05, 1.22) | 0.002 |
| Regional Lymph Nodes Examined | ||||||
| 0–11 | 1.34 | (1.29, 1.39) | <.0001 | 1.29 | (1.23, 1.35) | <.0001 |
| 12–90 | 1.00 | – | – | 1.00 | – | – |
| Chemotherapy | ||||||
| Yes | 1.00 | – | – | 1.00 | – | – |
| No | 3.55 | (3.41, 3.70) | <.0001 | 3.49 | (3.32, 3.67) | <.0001 |