"While Hispanics are generally known to have low rates of colorectal cancer screening relative to whites, we were surprised by the very low rate of screening in Asians, whose screening rates have not previously been well studied at a national level," said Anthony Jerant, associate professor of family and community medicine at UC Davis and lead author for the study. "Asians, Hispanics and blacks are clearly not tested nearly as much as they should be for colorectal cancer. The paths we can take to increase testing among blacks and Hispanics seem clear, but what is driving this disparity for Asians is not fully explained by traditional factors measured on national surveys, like language, age or insurance status. Our findings indicate we need to work on uncovering the other reasons why Asians are not participating in screening."
Disparities in cancer screening contribute to higher cancer incidence and death rates. Cancer diagnoses and deaths have decreased overall in recent years, a trend credited in part to effective prevention outreach. Increased colorectal cancer screening contributes to this trend because it leads to the early removal of polyps that could later become cancerous.
In an effort to better understand factors keeping some people from participating in colorectal cancer screening, Jerant and colleagues analyzed data from two national surveys conducted between 2000 and 2005. A total of 22,973 adults age 50 and older answered questions about demographics, screening behaviors and other social and health factors. Overall, 54.1 percent of the participants were screened for colorectal cancer using either colonoscopy or fecal occult blood testing. Colorectal cancer screening rates overall lag behind those for other cancer screening tests, and marked disparities exist between non-Hispanic whites and racial and ethnic minorities in the United States. Individuals in racial and ethnic minority groups were less likely than whites to be tested: 33.8 percent of Asians, 36.7 percent of Hispanics and 48.2 percent of blacks underwent a colorectal screening procedure within the recommended timeframe, compared with 57.2 percent of whites.
After adjusting for factors associated with screening -- including demographics, socioeconomic variables, language spoken at home, health care access and self-rated health -- disparities for blacks and Hispanics relative to whites essentially disappeared. Beyond socioeconomic factors, which disproportionately affect all minority groups, the findings suggest that improving access to care and, for Hispanics, providing language-appropriate care could have positive effects on increasing colorectal cancer screening. After adjusting for the same factors, however, disparities between whites and Asians lessened somewhat but still remained significant.
According to Jerant, the findings suggest that different types of outreach programs may improve screening rates in the various minority groups. Culturally targeted interventions for patients and physicians might help address Asian individuals, enhanced access to health care may help mitigate disparities between white and black patients, and both maximized access and language-appropriate care and information may greatly increase the number of Hispanics who are screened.
"Although this study design does not permit firm conclusions regarding the reason for this finding, the implication is that unmeasured cultural factors may contribute to the Asian/non-Hispanic white disparity in colorectal cancer screening," Jerant and co-authors write. "Less acculturated Asian individuals in the United States may have core health beliefs that differ from those in the 'Western' health model, leading them to decline fecal occult blood testing or endoscopy offered in the absence of worrisome symptoms. They may also be less likely to be offered colorectal cancer screening. Thus, culturally targeted interventions (focused on physicians and patients) might help address the Asian/non-Hispanic white colorectal cancer screening disparity."
Jerant recommends additional studies to further examine why Asians are not participating in lifesaving cancer prevention measures. The answers could be very different for Asian populations than for other minority groups in the United States.
A copy of the study "Determinants of Racial/Ethnic Colorectal Cancer Screening Disparities" can be downloaded at www.jamamedia.org or requested by calling JAMA/Archives media relations at (312) 464-JAMA (5262) or e-mailing mediarelations@jama-archives.org.
The UC Davis Department of Family and Community Medicine provides ongoing, comprehensive, compassionate and personal care for patients within the context of family and community. The medical team integrates a humanistic approach to treating the "whole person" with evidence-based care. Special areas of faculty research are health behavior change, physician-patient communication, chronic illness care, women's health issues and reducing racial and ethnic health disparities. For more information, visit www.ucdmc.ucdavis.edu.