Screening rates for colorectal cancer are lower in safety net health system, study reveals

Sep 8 2009

Colorectal cancer screening rates are much lower among those in a safety net health system compared to the national average, and the number one predictor of screening is a combination of regular visits and insurance access.

Colorectal cancer is the second leading cause of cancer death in the United States behind lung cancer. Nearly 50,000 Americans will die from colorectal cancer this year. Although scientists have differing opinions on the best method, the benefits of early screening are beyond debate — cancers caught early are easier to manage and treat.

Still, the nationwide rate of colorectal cancer screening is 61 percent, with much of the lack of screening concentrated among blacks, Hispanics and those without insurance. However, results of a study published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, showed that the screening rate was merely 22 percent among individuals served by a safety net health system in Texas.

"Of our patients who did get screened, they either had insurance or saw their doctor regularly. Once you controlled for those variables, the screening rate was essentially zero," said Samir Gupta, M.D., assistant professor in the Department of Internal Medicine at the University of Texas Southwestern Medical Center.

Gupta and colleagues conducted their study using data from the Tarrant County Hospital District John Peter Smith Hospital Health Network, a safety net health system. The system serves 155,000 individuals a year in Tarrant County, Texas, a geographic area that includes Fort Worth, and is committed to delivering health care to the uninsured, Medicaid and other vulnerable patients.

Using their electronic administrative records, Gupta and colleagues identified 20,416 patients who were between 54 and 75 years old and were eligible for colorectal cancer screening. The median age of these patients was 60 years, and about 60 percent of them were women. Approximately 15 percent of the population lived below the poverty line and median household income was $35,419. The majority of the patients were either black or Hispanic; nearly 20 percent reported a primary language other than English.

Although 40 percent were classified as having health insurance, including those on Medicare and Medicaid, another 40 percent only had medical coverage through their connection to the safety net system; 20 percent had no insurance at all.

Over the previous five years, 22 percent of these patients were screened for colorectal cancer. Women were slightly more likely than men, and Hispanics were slightly more likely to be screened than whites, but the largest increase came when insurance and regular medical care were considered. Those with insurance were almost three times as likely to be screened, and those who saw the doctor regularly were nearly four times as likely to be screened.

Karen Glanz, Ph.D., M.P.H., professor of medicine and nursing at the University of Pennsylvania and an editorial board member of Cancer Epidemiology, Biomarkers & Prevention, said this study documents an important issue in a specific population.

"The idea that colorectal cancer screening rates are too low is not a new idea, but this is one of the first to document it in a specific population," said Glanz. "Access to care clearly has consequences, and any talk of health care reform needs to address proven prevention measures like screening."

Gupta said a national model already exists for successful screening. Low income, uninsured and underserved women can get breast and cervical cancer screening through the Centers for Disease Control's National Breast and Cervical Cancer Early Detection Program, but Gupta said such an approach is far too disease-specific.

"Theoretically, the same model could be applied to colorectal cancer, but do we want to keep passing legislation for programs that target specific types of cancer, or could we provide more broad access to health care so we can make a serious and coordinated effort at prevention?" said Gupta. "That's the question that needs answering."