In a study reported in JAMA Oncology, Michael S. Leapman, MD, and colleagues found that sociodemographic factors (like geographic area of residence) as well as manifestations of structural racism (like poverty and racial segregation) accounted for the majority of differences in the use of magnetic resonance imaging (MRI) in older Black vs White men diagnosed with localized prostate cancer.
Study Details
The population-based cohort study used mediation analysis to assess claims in the SEER (Surveillance, Epidemiology, and End Results)-Medicare database for prostate MRI within 6 months before or after diagnosis of prostate cancer among 39,534 patients (3,979 Black and 32,585 White) diagnosed with localized prostate cancer from January 2011 to December 2015. Candidate mediators included the Index of Concentration at the Extremes (ICE), used to measure racialized residential segregation; the lowest ICE quintile areas have the highest proportion of Black residents relative to White residents.
Michael S. Leapman, MD
Key Findings
Prostate MRI use increased during the study period, from 5.3% of patients diagnosed in 2011 to 17.5% of those diagnosed in 2015. Overall, prostate MRI was received by 6.3% of Black patients vs 9.9% of White patients, with an unadjusted odds ratio of 0.62 (95% confidence interval [CI] = 0.54–0.70). After adjustment for available clinical and sociodemographic variables, the odds ratio was 0.88 (95% CI = 0.76–1.03).
Approximately 24% (95% CI = 14%–32%) of the disparity in use was attributable to geographic differences (SEER registry). For example, use of MRI occurred in 14.9% of Black patients vs 27.5% of white patients in the Los Angeles registry, and in 9.2% vs 9.5% in the Atlanta registry.
Approximately 19% (95% CI = 11%–28%) of the disparity was attributable to neighborhood-level socioeconomic status (residence in a high-poverty area), 19% (95% CI =10%–29%) to racialized residential segregation (ICE quintile), and 11% (95% CI = 7%–16%) to dual eligibility for Medicare and Medicaid (a marker of individual-level socioeconomic status).
Overall, the above mediators accounted for approximately 81% (95% CI = 64%–98%) of the disparity in MRI use. Clinical and pathologic factors were not significant mediators of disparity in use of MRI.
The investigators concluded, “In this population-based cohort study of U.S. adults, mediation analysis revealed that sociodemographic factors and manifestations of structural racism, including poverty and residential segregation, explained most of the racial disparity in the use of prostate MRI among older Black and White men with prostate cancer. These findings can be applied to develop targeted strategies to improve cancer care equity.”
Dr. Leapman, of the Department of Urology, Yale School of Medicine, is the corresponding author for the JAMA Oncology article.
Disclosure: The study was funded by the National Cancer Institute. For full disclosures of the study authors, visit jamanetwork.com.
