Background: Women without private health insurance are less likely than privately insured women to be screened for breast cancer, and their treatment may differ after cancer is diagnosed. In this study we addressed two related questions: Do uninsured patients and those covered by Medicaid have more advanced breast cancer than privately insured patients when the disease is initially diagnosed? And, for each stage of disease, do uninsured patients and patients covered by Medicaid die sooner after breast cancer is diagnosed than privately insured patients?
Methods: We studied 4675 women, 35 to 64 years of age, in whom invasive breast cancer was diagnosed from 1985 through 1987, by linking New Jersey State Cancer Registry records to hospital-discharge data. We compared the stage of disease and stage-specific survival among women with private insurance, no insurance, and Medicaid coverage through June 1992. We also estimated the adjusted risk of death for these groups, using proportional-hazards regression analysis to control for age, race, marital status, household income, coexisting diagnoses, and disease stage.
Results: Uninsured patients and those covered by Medicaid presented with more advanced disease than did privately insured patients (P < 0.001 and P = 0.01, respectively). Survival was worse for uninsured patients and those with Medicaid coverage than for privately insured patients with local disease (P < 0.001 for both comparisons) and regional disease (P < 0.001 for both comparisons), but not distant metastases. The adjusted risk of death was 49 percent higher (95 percent confidence interval, 20 to 84 percent) for uninsured patients and 40 percent higher (95 percent confidence interval, 4 to 89 percent) for Medicaid patients than for privately insured patients during the 54 to 89 months after diagnosis.
Conclusions: The more frequent adverse outcomes of breast cancer among women without private health insurance suggest that such women would benefit from improved access to screening and optimal therapy.