New research from UTHealth Houston shows that populations in U.S. counties that are considered more vulnerable due to socioeconomic and racial/ethnicity status were significantly less likely to receive regular and timely breast cancer, cervical cancer, and colorectal cancer screenings. The research was led by Cici Bauer, PhD, associate professor of biostatistics and data science, and Ryan Suk, PhD, assistant professor of management, policy and community health, both of UTHealth School of Public Health.
The new research, published in JAMA Network Open, found regional disparities in screening rates at a county level in more than 3,100 counties ranging from the lowest-performing county to the highest, including from 54.0% to 81.8% for breast cancer screening, from 69.9% to 89.7% for cervical cancer screening, and from 39.8% to 74.4% for colorectal cancer screening.
“Even though cervical cancer screening rates are high overall, that doesn’t mean that is true everywhere,” Suk said. “Some populations have very low uptake, while in other areas, the cancer screening rate is higher than the national target rate. That’s why we have to focus on these differences by social determinants of health and not only overall average values.”
The investigators used the social vulnerability index (SVI) for their study. THE SVI uses U.S. Census data to calculate social vulnerability at a county or census tract level. It uses factors such as socioeconomic status, household composition, racial/ethnic minority status, housing type, transportation access, language barriers, among others in an area’s population. The score is a valuable tool for both public health officials and those working in plan and prepare for events such as catastrophic weather emergencies and disease outbreaks, which are known to disproportionately affect regions with higher SVIs.
“We found that counties with higher SVI scores had significantly lower screening rates for all three types of cancer,” Suk said. “These findings suggest that geographically targeted public health interventions could be further informed and improved by a composite measure reflecting the multidimensional measure of area-level social determinants of health.”
In addition, the study showed that the likelihood of having cancer screening in the most vulnerable quintile of the study compared with the least vulnerable quintile was 14% lower for breast cancer, 20% lower for cervical cancer, and 28% lower for colorectal cancer. Also, while other area-level factors including rural versus urban residence and access to health care were also associated with lower screening rates, they did not further explain the geographic variation of the cancer screenings and did not change the association between social vulnerability and cancer screening rates.
In general, screening rates for all three cancer types studied were higher on the East and West coasts of the U.S. and lower in the South.
“Our study emphasizes the benefit of using geospatial analysis in population health for cancer research. It provides a powerful analytical tool to identify target areas for improving cancer prevention and reducing disparities,” Bauer said. “It also provides a way to understand how various social determinants of health may impact the cancer-related outcomes.