Effects of health insurance and race on early detection of cancer.

BACKGROUND: The presence and type of health insurance may be an important determinant of cancer stage at diagnosis. To determine whether previously observed racial differences in stage of cancer at diagnosis may be explained partly by differences in insurance coverage, we studied all patients with incident cases of melanoma or colorectal, breast, or prostate cancer in Florida in 1994 for whom the stage at diagnosis and insurance status were known.
METHODS: The effects of insurance and race on the odds of a late stage (regional or distant) diagnosis were examined by adjusting for an individual's age, sex, marital status, education, income, and comorbidity. All P values are two-sided.
RESULTS: Data from 28 237 patients were analyzed. Persons who were uninsured were more likely diagnosed at a late stage (colorectal cancer odds ratio [OR] = 1.67, P =.004; melanoma OR = 2.59, P =.004; breast cancer OR = 1.43, P =.001; prostate cancer OR = 1.47, P =.02) than were persons with commercial indemnity insurance. Patients insured by Medicaid were more likely diagnosed at a late stage of breast cancer (OR = 1.87, P<.001) and melanoma (OR = 4.69, P<.001). Non-Hispanic African-American patients were more likely diagnosed with late stage breast and prostate cancers than were non-Hispanic whites. Hispanic patients were more likely to be diagnosed with late stage breast cancer but less likely to be diagnosed with late stage prostate cancer.
CONCLUSIONS: Persons lacking health insurance and persons insured by Medicaid are more likely diagnosed with late stage cancer at diverse sites, and efforts to improve access to cancer-screening services are warranted for these groups. Racial differences in stage at diagnosis are not explained by insurance coverage or socioeconomic status.