Cancer stage comparison between dual Medicare-Medicaid eligibles using Medicaid as a supplemental health insurance program and low-income nonduals.

Background: Dual-eligibility status for both Medicare and Medicaid is associated with unfavorable cancer stage outcomes. However, given the reduced financial barriers, duals enrolled in Medicaid prior to cancer diagnosis-or those using Medicaid as a supplemental health insurance program (Dual/SHIP)-may have improved access to preventive services compared with low-income nonduals (LI/nondual), therefore, be more likely to be diagnosed at earlier stages of cancers amenable to screening.

Objectives: To compare breast, prostate, and colorectal cancer stage at diagnosis between Duals/SHIP and LI/nonduals, adjusting for sociodemographic variables, comorbidities, and nursing home status.

Research Design: Cross-sectional study using a database developed by linking records from the Ohio Cancer Incidence Surveillance System with Medicare and Medicaid files, as well as US census data.

Subjects: Fee-for-service, Ohio residents aged 65 years or older, and diagnosed with incident breast, prostate, or colorectal cancer in 1997-2001.

Measures: (1) Unknown stage/unstaged cancer and (2) distant-stage cancer at diagnosis.

Results: Duals/SHIP were more likely than LI/nonduals to have unknown stage/unstaged breast cancer (adjusted odds ratio: 1.43, 95% Confidence Interval (CI): 1.02-2.0; P = .035). However, this difference was not seen in prostate or colorectal cancer. In prostate cancer patients, but not in breast or colorectal cancer patients, Dual/SHIP status was associated with distant-stage disease (adjusted odds ratio: 1.74, 95% CI: 1.12-2.70; P = .014). In colorectal cancer patients, dual status was not associated with cancer stage.

Conclusion: The findings show no benefit associated with Medicaid as SHIP. Rather, they indicate that for the most part, cancer stage is comparable between Duals/SHIP and LI/nonduals.