Insurance status and survival disparities among nonelderly rectal cancer patients in the National Cancer Data Base.

BACKGROUND

Among patients with colorectal cancer, insurance status is associated with disparities in survival as well as differences in stage and treatment. The role of stage and treatment differences in these survival disparities is not clear because insurance status is also strongly correlated with race/ethnicity, socioeconomic status, and other factors.

METHODS

The authors used data from the National Cancer Data Base, a national hospital-based cancer registry, to examine insurance status and other factors related to survival among 19,154 rectal cancer patients aged 18 to 64 years. The authors examined the impact of 10 factors on 5-year survival: age, sex, race/ethnicity, histologic grade, histologic subtype, neighborhood education and income levels, facility type, stage, and treatment.

RESULTS

Adjusted only for age, the hazard ratio (HR) for death at 5 years was 1.00 (referent) among privately insured patients, 2.05 (95% confidence interval [CI], 1.89-2.23) among Medicaid-insured patients, and 2.01 (95% CI, 1.84-2.19) among uninsured patients. After adjustment for all factors other than stage and treatment, the HRs were 1.88 (95% CI, 1.722.04) for Medicaid-insured patients and 1.84 (95% CI, 1.69-2.01) for uninsured patients. After further adjustment for stage and treatment, the HRs were 1.34 (95% CI, 1.22-1.46) for Medicaid-insured patients and 1.29 (95% CI, 1.18-1.42) for uninsured patients.

CONCLUSIONS

After adjustment for age, further adjustment for 9 other factors reduced the excess mortality among rectal cancer patients without private insurance by approximately 70%. Disparities in stage and treatment accounted for approximately 53% of the excess mortality, whereas factors other than stage and treatment accounted for approximately 17%.