The study findings suggest that language, socio-demographics, and to some extent, access to care may explain the disparity in CRC screening between Hispanics and non-Hispanic whites in the U.S. Furthermore, it appears that the contribution of each of these factors to CRC screening disparities varies by national origin among Hispanics. The analyses were conducted using a large, nationally-representative data set that included sufficient numbers of people reporting Cuban, Puerto Rican, Mexican, or Dominican origin to examine the sources of CRC screening disparities in Hispanic subgroups. Thus, these findings begin to reconcile the conflicting results of prior studies exploring the correlates of CRC screening disparities.11–19
A main goal of disparity research is to yield findings that might inform interventions aimed at eliminating the disparities. Our findings should be helpful in guiding public health policy and health care delivery intervention efforts to mitigate the disparity in CRC screening between Hispanics and non-Hispanic whites. They underscore that variations in health behaviors may be as great among individuals within
major racial/ethnic groups as between racial/ethnic groups.32
Thus, developing disparity reduction strategies based solely
on broad racial/ethnic group characteristics may be misguided. Personally tailored interventions to address barriers to CRC screening, provided within a culturally salient framework in the user’s preferred language, have the potential to address both inter- and intra-racial/ethnic group variability. Though as yet unproven, such interventions, therefore, hold promise as a way of mitigating disparities in screening among groups.33
Our findings differ from those of Gorin and Heck,27
who found people of Puerto Rican and Central/South American origin were half as likely as those of Cuban, Dominican, and Mexican origin to be up to date for endoscopic screening. They also found no significant differences by national/regional origin in being up to date for FOBT. However, their study used 2000 NHIS data. Substantial secular increases in CRC screening overall in the U.S. since 2000,1
along with the rapid growth and change in the U.S. Hispanic population since 2000,34
are likely to explain why their findings differed from ours. Further, their analyses did not include data for non-Hispanic whites, limiting their usefulness to those seeking to address the disparity in CRC screening between Hispanics and non-Hispanic whites.
The reasons for the association between interview language (Spanish versus English) and CRC screening are unclear. The respondent’s choice of language may reflect cultural preferences. On the other hand, language might simply represent a barrier to obtaining optimal care. These potential explanations imply different approaches to remedying disparities, and each might be operative to varying degrees among different Hispanic subgroups. Further studies designed to explore this issue are needed.
We also note that differences in endoscopy between Hispanics and non-Hispanics were greater than differences in FOBT, echoing the results of other studies.9,19
These findings provide evidence of a technology diffusion gap between Hispanics and non-Hispanics. It remains unclear whether the gap exists due to limited access to screening endoscopy for Hispanics relative to others, or less access to follow-up endoscopy (e.g., after abnormal FOBT or to evaluate worrisome symptoms), or a combination of these factors. Regardless, such a technology diffusion gap may contribute, along with the overall CRC screening disparities presented here, to the increased risk of advanced stage CRC cancer and CRC mortality in Hispanics relative to non-Hispanic whites observed in some studies.10
Study Limitations and Strengths
In addition to its previously mentioned strengths, our study had several limitations. MEPS data are cross-sectional, precluding causal conclusions regarding the associations among language, socio-demographics, access to care, and CRC screening. The sample size for persons of Dominican national origin was small, so conclusions for this group are tentative. Also, the response rate for the MEPS is about 65%, and it is therefore possible that participants, particularly Hispanics, differ from their non-participant counterparts. While the direction and size of this effect is unknown, and could well vary among Hispanic national origin groups, it may lead to under-estimation of the disparity in CRC screening between Hispanics and non-Hispanic whites.
MEPS data also include only limited geographic detail. We could only adjust for geographic region (Northeast, Midwest, South, or West) because more finely grained information (e.g., state of residence) is not made available in the MEPS database due to confidentiality concerns. This may be problematic given marked differences in the geographic distribution of various Hispanic ethnic groups in the U.S., and in light of the considerable variation in medical practices across the U.S. Nonetheless, the data regarding geographic region by ethnicity presented in Table suggest the potential for confounding even by broad geographic region, and our models adjusted for such confounding.
Finally, we note limitations in our key outcome variables, receipt of FOBT and endoscopy, which rely on self-report, which correlates only modestly with claims data.35, 36
It is plausible that response bias (e.g., due to social desirability) may affect the various national origin groups differently, contributing to a biased estimate of the disparities.35
Moreover, it is not possible to determine in MEPS data whether respondents who indicate receiving endoscopy underwent colonoscopy (currently recommended every 10 years in most but not all guidelines) or flexible sigmoidoscopy (currently recommended every 5 years in most guidelines).31
Due to these limitations in MEPS endoscopy data, and because the currently recommended intervals for endoscopic CRC screening tests are not firmly evidence-based,31
we conservatively defined up to date status for endoscopic screening as receipt of endoscopy at any time. We also used a generous definition for up to date FOBT status. However, these definitions resulted in relatively few additional persons being categorized as up to date beyond the number so classified using a 1-year interval for FOBT and a 5-year interval for endoscopy. Moreover, repeated analyses using these definitions gave qualitatively similar results (data not shown). Finally, MEPS questions regarding endoscopy do not distinguish between screening and testing to evaluate symptoms. Thus, the rates of CRC screening reported here, as in other national self-report surveys, are likely to be inflated. The extent to which inflation varies among study subgroups is unknown.