For uninsured American Indians and Alaskan Natives (AIAN) diagnosed with cancer, prompt enrollment in Medicaid may speed access to treatment and improve survival. We hypothesized that AIANs who were eligible for the Indian Health Service Care System (IHSCS) at cancer diagnosis may be enrolled in Medicaid sooner than other AIANs.
Using Washington, Oregon, and California State Cancer Registries, we identified AIANs with a primary diagnosis of lung, breast, colorectal, cervical, ovarian, stomach, or prostate cancer between 2001 and 2007. Among AIANs enrolled in Medicaid within 365 days of a cancer diagnosis, we linked cancer registry records with Medicaid enrollment data and used a multivariate logistic regression model to compare the odds of delayed Medicaid enrollment between those with (n = 223) and without (n = 177) IHSCS eligibility.
Among AIANs who enrolled in Medicaid during the year following their cancer diagnosis, approximately 32% enrolled >1 month following diagnosis. Comparing those without IHSCS eligibility to those with IHSCS eligibility, the adjusted odds ratio (OR) for moderately late Medicaid enrollment (between 1 and 6 months after diagnosis) relative to early Medicaid enrollment (=1 month after diagnosis) was 1.10 [95% confidence interval (CI), 0.62-1.95] and for very late Medicaid enrollment (>6 months to 12 months after diagnosis), OR was 1.14 (CI, 0.54-2.43).
IHSCS eligibility at the time of diagnosis does not seem to facilitate early Medicaid enrollment.
Because cancer survival rates in AIANs are among the lowest of any racial group, additional research is needed to identify factors that improve access to care in AIANs.
Nationally, a greater proportion of American Indians and Alaska Natives (AI/ANs) are diagnosed with advanced-stage cancers compared with non-Hispanic whites. The reasons for observed differences in stage at diagnosis between AI/ANs and non-Hispanic whites remain unclear.
Medicaid, Indian Health Service Care Systems, and state cancer registry data for California, Oregon, and Washington (2001-2008, analyzed in 2014-2015) were linked to identify AI/ANs and non-Hispanic whites diagnosed with invasive breast, cervical, colorectal, lung, or prostate cancer. Logistic regression was used to estimate ORs and 95% CIs for distant disease versus local or regional disease, in AI/ANs compared with non-Hispanic white case patients.
A similar proportion of AI/AN (31.2%) and non-Hispanic white (35.5%) patients were diagnosed with distant-stage cancer in this population (AOR=1.03, 95% CI=0.88, 1.20). No significant differences in stage at diagnosis were found for any individual cancer site. Among AI/ANs, Indian Health Service Care Systems eligibility was not associated with stage at diagnosis.
In contrast to the general population of the U.S., among Medicaid enrollees, AI/AN race is not associated with later stage at diagnosis. Cancer survival disparities associated with AI/AN race that have been observed in the broader population may be driven by factors associated with income and health insurance that are also associated with race, as income and insurance status are more homogenous within the Medicaid population than within the broader population.