Disparities in Cancer Screening Rates Associated with US County Social Vulnerability Index
Populations in U.S. counties defined as more vulnerable based on social factors, including socioeconomic status and racial/ethnic minority status, were significantly less likely to receive timely breast, cervical cancer screenings. uterus and colorectal, according to a study by UTHealth Houston.
The results were published today in JAMA network open.
Disparities in testing rates were strongly associated with a county’s Social Vulnerability Index (SVI) – a tool that uses US Census data to determine social vulnerability at a county or ward level census. SVI is calculated using factors such as socio-economic status, household composition, racial/ethnic minority status, housing type, access to transportation, language barriers, etc. among the population of a region. The index score helps public health officials and local planners better prepare for and respond to emergency events such as hurricanes and disease outbreaks, which disproportionately affect areas with higher SVIs .
The study 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 at the UTHealth School of Public Health.
We found that counties with higher SVI scores had significantly lower screening rates for all three cancer types. These results suggest that geographically targeted public health interventions could be further informed and improved by a composite measure reflecting the multidimensional measure of social determinants of health at the regional level.
Ryan Suk, PhD, Assistant Professor of Management, Policy, and Community Health, UTHealth School of Public Health
Researchers found regional disparities in county-level cancer screening rates across 3,141 U.S. counties, ranging from lowest to highest performing county, including 54.0% to 81.8% for cancer screening. breast cancer, 69.9% to 89.7% for cervical cancer screening, and 39.8% to 74.4% for colorectal cancer screening.
“Even though cervical cancer screening rates are high overall, that doesn’t mean it’s true everywhere,” Suk said. “Some populations have very low uptake, while in other areas the cancer screening rate is above the national target rate. This is why we need to focus on these differences according to the social determinants of health and not just on the overall mean values.
The population-based, cross-sectional study used county-level information from the Centers for Disease Control and Prevention’s PLACES and SVI datasets from 2018 for counties. The analyzes were conducted from October 2021 to February 2022.
Other key findings include:
- The likelihood of having a cancer screening in the most vulnerable counties (or the top fifth) compared to the least vulnerable counties (the bottom fifth) was 14% lower for breast cancer, 20% lower for cervical cancer and 28% lower for colorectal cancer.
- Some other region-level factors, such as rural/urban status and access to health care in the county, were also associated with cancer screening rates. However, these factors did not further explain the geographic variation in cancer screenings and did not alter the association between social vulnerability and cancer screening rates.
In general, all three cancer screening rates were higher in the east and west coast counties 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 to improve cancer prevention and reduce disparities,” Bauer said. “It also provides a means of understanding how various social determinants of health may impact cancer-related outcomes.”
Overall, colorectal cancer screening rates were low in the United States, Suk said, which means public health experts should stress the importance of such large-scale screenings.
Co-authors with the UTHealth School of Public Health included Kehe Zhang, MPH; Qian Xiao, Ph.D., MPH; and Jiachen Lu, MS. Young-Rock Hong, PhD, MPH, of the University of Florida, also contributed.
University of Texas Health Sciences Center at Houston
Bauer, C. et al. (2022) County-Level Social Vulnerability and Screening Rates for Breast, Cervical, and Colorectal Cancer in the United States, 2018. JAMA network open. doi.org/10.1001/jamanetworkopen.2022.33429.