Cancer survival disparities by health insurance status

Abstract

Previous studies found that uninsured and Medicaid insured cancer patients have poorer outcomes than cancer patients with private insurance. We examined the association between health insurance status and survival of New Jersey patients 18-64 diagnosed with seven common cancers during 1999-2004. Hazard ratios (HRs) with 95% confidence intervals for 5-year cause-specific survival were calculated from Cox proportional hazards regression models; health insurance status was the primary predictor with adjustment for other significant factors in univariate chi-square or Kaplan-Meier survival log-rank tests. Two diagnosis periods by health insurance status were compared using Kaplan-Meier survival log-rank tests. For breast, colorectal, lung, non-Hodgkin lymphoma (NHL), and prostate cancer, uninsured and Medicaid insured patients had significantly higher risks of death than privately insured patients. For bladder cancer, uninsured patients had a significantly higher risk of death than privately insured patients. Survival improved between the two diagnosis periods for privately insured patients with breast, colorectal, or lung cancer and NHL, for Medicaid insured patients with NHL, and not at all for uninsured patients. Survival from cancer appears to be related to a complex set of demographic and clinical factors of which insurance status is a part. While ensuring that everyone has adequate health insurance is an important step, additional measures must be taken to address cancer survival disparities.

Keywords: Bladder cancer; breast cancer; cervical cancer; colorectal cancer; disparities; insurance status; lung cancer; non-Hodgkin lymphoma; prostate cancer; survival.

Figure 1

Five-year cause-specific survival rates by health insurance status for each cancer type, New Jersey, 1999–2004. The rates were significantly different by insurance status for each cancer type (Kaplan–Meier log-rank tests, P < 0.0001). The total numbers of cancers and cause-specific 5-year rates are labeled in each figure.