Table 2.
Multivariable Linear Regression Models Evaluating Factors Associated With County-Level Age-Adjusted GI Cancer–Related Mortality Rates
| Esophagus cancer |
Stomach cancer |
Pancreas cancer |
Colorectal cancer |
|||||
|---|---|---|---|---|---|---|---|---|
| County-level variable | Beta coefficient (95% CI) |
P value | Beta coefficient (95% CI) |
P value | Beta coefficient (95% CI) |
P value | Beta coefficient (95% CI) |
P value |
| Patient factors | ||||||||
| % male | 0.07 (0.01, 0.11) | <.01 | NS | - | NS | - | NS | - |
| Racial composition | ||||||||
| % White Hispanic | −0.02 (−0.04, −0.01) | <.001 | 0.05 (0.04, 0.06) | <.001 | NS | - | NS | - |
| % Black non-Hispanic | −0.03 (−0.03, −0.02) | <.001 | 0.05 (0.05, 0.06) | <.001 | 0.05 (0.04, 0.06) | <.001 | 0.03 (0.01, 0.05) | <.001 |
| % Black Hispanic | NS | - | NS | - | NS | - | NS | - |
| % Asian | −0.03 (−0.06, −0.003) | .003 | 0.06 (0.04, 0.08) | <.001 | NS | - | NS | - |
| % Native American | −0.04 (−0.06, −0.02) | <.001 | 0.09 (0.07, 0.10) | <.001 | −0.03 (−0.06, 0.004) | .09 | NS | - |
| % with diabetes | NS | - | 0.16 (0.09, 0.23) | <.001 | NS | - | 0.31 (0.12, 0.48) | <.001 |
| % with obesity | 0.12 (0.09, 0.15) | <.001 | NS | - | 0.10 (0.05, 0.15) | <.001 | 0.26 (0.17, 0.34) | <.001 |
| % cigarette use | 0.10 (0.06, 0.13) | <.01 | 0.06 (0.04, 0.09) | <.001 | 0.15 (0.11, 0.20) | <.001 | 0.40 (0.34, 0.46) | <.001 |
| % heavy alcohol use | 0.18 (0.14, 0.22) | <.001 | NS | - | 0.09 (0.02, 0.15) | .01 | NS | - |
| Systemic factors | ||||||||
| Rural/urban | ||||||||
| Large metropolitan | Reference | - | Reference | - | Reference | Reference | - | |
| Small/medium metropolitan | −0.07 (−0.29, 0.14) | .50 | −0.20 (−0.35, −0.05) | .008 | −0.36 (−0.75, 0.04) | .08 | −0.67 (−1.24, −0.10) | .02 |
| Rural | 0.56 (0.33, 0.79) | <.001 | 0.52 (0.32, 0.72) | <.001 | 0.13 (−0.26, 0.52) | .51 | 1.77 (1.22, 2.31) | <.001 |
| % uninsured | −0.05 (−0.07, −0.03) | <.001 | −0.03 (−0.05, −0.02) | <.001 | −0.08 (−0.11, −0.06) | <.001 | NS | - |
| % living below federal poverty level | NS | - | NS | - | NS | - | NS | - |
| Travel time to nearest NCI cancer centera | 0.03 (−0.005, 0.06) | .09 | NS | - | 0.04 (−0.01, 0.10) | .09 | NS | - |
| Specialist density per 100,000 population | ||||||||
| Gastroenterologists | NS | - | NS | - | NS | - | NS | - |
| Radiation oncologists | NS | - | NS | - | NS | - | NS | - |
| Colorectal surgeons | NA | - | NA | - | NA | - | NA | - |
| % colon cancer Screening | NA | - | NA | - | NA | - | −0.03 (−0.07, 0.003) | .07 |
| Overall model R2 | 0.43 | 0.61 | 0.14 | 0.39 | ||||
NOTE. Beta coefficients with a positive value associated with increased county-level cancer-related mortality. Covariables that were not included had P > .1 in univariable analysis or did not increase overall R2 in multivariable models fit by backward selection.
NA, not applicable; NS, not significant on univariable modelling and covariable not included in final model.
a
Travel time defined by per unit increase of 30 min from county centroid to nearest National Cancer Institute Comprehensive Cancer Center.