Background: Under-representation of minority populations in research utilizing biospecimens can prohibit advancements in cancer research, treatment and survivorship from reaching those who are most vulnerable, potentially increasing cancer health disparities. Barriers and facilitators to biospecimen provision among under-represented populations are not well understood. This study examined predictors of biospecimen provision in a large cohort of black women.

Methods: The Black Women's Health Study (BWHS), an ongoing prospective cohort study of African American women from across the U.S. followed since 1995, initiated a four-year effort in 2013 to collect blood biospecimens. Of 48,956 BWHS participants invited to provide a blood sample, 27% (n=13,037) did so. We used logistic regression analyses to estimate multivariable odds ratios (OR) and 95% confidence intervals (CI) for associations of participant characteristics with sample provision, adjusted for age and education.

Results: The strongest predictors of providing a blood sample were having had a physical exam in the past two years (OR 3.90 [95% CI 3.70-4.11]), and, independently, mammographic screening in the past two years (OR 1.88 [1.76-2.01]). Other predictors included educational status (OR 1.30 [1.21-1.39] for >16 vs. ≤12 years of education) and having a family history of cancer (OR 1.16 [1.11-1.21]). Women had lower odds of giving a blood sample if they reported more frequent experiences of racism in their daily lives (OR 0.83 [0.77-0.89] for highest vs. lowest level of racism score) or lived in a rural vs. urban area (OR 0.75 [0.69-0.80]). History of cancer was not associated with sample provision. Because interaction with the health care system was such a strong predictor, we repeated analyses restricted to those who had not reported a recent physical exam. No new associations emerged, but both mammographic screening (OR 4.23 [3.81-4.70]) and daily racism (OR 0.64 [0.55-0.75]) became stronger predictors in this group.

Conclusions: Recent utilization of the health care system and higher levels of education were the strongest predictors of agreement to provide a blood sample for research in this cohort of black women, while living in a rural area and having more frequent experiences of racism, a unique characteristic of this population, were barriers. Innovative recruitment efforts may be necessary for greater inclusion of individuals who are less educated and infrequent users of the health care system. In addition, the persistent reality of racism in the U.S. may continue to play a role in the under-representation of black Americans in cancer research utilizing biospecimens.

Citation Format: Lauren E. Barber, Julie R. Palmer, Kimberly A. Bertrand, Catharine Wang. Predictors of blood biospecimen provision among African American women [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C040.