Background: Engaging diverse populations in biomedical research, including biospecimen donation, remains a national challenge. This study examined factors associated with an invitation to participate in biomedical research, intent to participate in biomedical research in the future, and participation in biomedical research and biospecimen donation among a diverse, multilingual, community‐based sample across 3 distinct geographic areas.Methods: Three National Cancer Institute–designated cancer centers engaged in community partnerships to develop and implement population health assessments, reaching a convenience sample of 4343 participants spanning their respective catchment areas. Data harmonization, multiple imputation, and multivariable logistic modeling were used.Results: African Americans, Hispanic/Latinos, and other racial minority groups were more likely to be offered opportunities to participate in biomedical research compared to whites. Access to care, history of cancer, educational level, survey language, nativity, and rural residence also influenced opportunity, intent, and actual participation in biomedical research.Conclusions: Traditionally underserved racial and ethnic groups reported heightened opportunity and interest in participating in biomedical research. Well‐established community partnerships and long‐standing community engagement around biomedical research led to a diverse sample being reached at each site and may in part explain the current study findings. However, this study illustrates an ongoing need to establish trust and diversify biomedical research participation through innovative and tailored approaches. National Cancer Institute–designated cancer centers have the potential to increase opportunities for diverse participation in biomedical research through community partnerships and engagement. Additional work remains to identify and address system‐level and individual‐level barriers to participation in both clinical trials and biospecimen donation for research.

Background: In the United States, there are lower rates of breastfeeding among African American mothers, particularly those who are younger women. Recent epidemiological studies have shown a strong association of more aggressive types of breast cancer (estrogen receptor negative) among African American women, with a higher risk in African American women who did not breastfeed their children. Objective: This study aims to describe the process evaluation of recruitment and educational strategies to engage pregnant African American participants for a pilot study designed to determine whether social media messaging about breast cancer risk reduction through breastfeeding may positively influence breastfeeding rates. Methods: This pilot study is conducted in collaboration with a local Women, Infants, and Children (WIC) organization and hospital and prenatal clinics of a local health care network. To engage African American women to enroll in the study, several methods and monitoring processes were explored, including WIC electronic text-based messages sent out to all phones of current WIC recipients (referred to as e-blasts); keyword responses to texts from flyers and posters in local community-based organizations, hospitals, and prenatal clinics; keyword responses using electronic links posted in established Facebook groups; and snowball recruitment of other pregnant women by current participants through Facebook. Once enrolled, participants were randomized to 2 study conditions: (1) an intervention group receiving messages about breast cancer risk reduction and breastfeeding or (2) a control group receiving breastfeeding-only messages. Data were obtained through electronic monitoring, SurveyMonkey, qualitative responses on Facebook, focus groups, and interviews. Results: More than 3000 text messages were sent and received through WIC e-blasts and keyword responses from flyers. A total of 472 women were recruited through WIC e-blast, and 161 responded to flyers and contacts through the local health care network, community-based organizations, Facebook, and friend referrals. A total of 633 women were assessed for eligibility to participate in the study. A total of 288 pregnant African American women were enrolled, consented, and completed presurvey assessments (102.8% of the goal), and 22 participants attended focus groups or interviews reporting on their experiences with Facebook and the educational messages. Conclusions: This process evaluation suggests that using electronic, smartphone apps with social media holds promise for both recruitment and conduct of health education intervention studies for pregnant African American women. Providing messaging and resources through social media to reinforce and educate women about breastfeeding and potentially provide lactation support is intriguing. Convenience (for researchers and participants) is an attribute of social media for this demographic of women and worthy of further research as an educational tool. Trial Registration: ClinicalTrials.gov NCT03680235; https://clinicaltrials.gov/ct2/show/NCT03680235