Abstract A040: Exploring intervention dosage and participant-driven mammography promotion: Early findings from the MADRE study
Abstract
Multiple approaches have been used to address Latinas’ disproportionate breast cancer burden, including patient navigation and community education. Recent research has suggested these individual-level interventions often have unmeasured “ripple” multilevel effects, through activating participants as change agents. Little is known about how intervention dosage – i.e., the amount of the proposed intervention and available support participants receive - predicts participants’ behaviors in promoting health. To examine if intervention dosage predicts mammography promotion among participants enrolled in a breast cancer screening trial. The parent study, MADRE, is a comparative effectiveness trial in Chicago. Eligibility criteria include: 1) age of 42-74; 2) no mammography use within past 2 years; 3) no previous breast cancer diagnosis; and, 4) no prior health volunteerism experience. All participants received CHW education and access to continuous patient navigation for mammography associated social and structural barriers (e.g., insurance, transportation). For the current secondary analysis, we focus on participants who completed post-intervention surveys, after participating in 3 CHW educational sessions. The outcome (mammography promotion) was measured as self-reported breast health promotion, using a validated instrument that minimizes recall and social desirability bias. The predictor (intervention dosage) was measured through study logs, which recorded the amount of navigation services received and successful engagement of post-intervention contact with CHWs and other staff, beyond navigation services. Multivariate logistic regression was conducted using SPSS (version 30.0) to examine factors associated with mammogram promotion. All analyses accounted for cohort clustering and adjusted for relevant covariates (age, income, education). There was a total of 295 women who enrolled in the study and completed post-intervention surveys. Approximately 45% of participants were 52-64 years old, 65% were insured, 25% had less than a 9th grade education, had an annual household income of <$15,000 (27%), and 65% were born in Mexico. Mammography promotion was predicted by intervention dosage indicators, including number of successful contacts with navigators (OR=1.41, 95%CI[1.00, 1.97], p=.004) and contact overall post-intervention (OR=1.38, 95%CI[1.10, 1.72], p=.004). Results suggest that even limited and phone-based contact with patient navigators can contribute to spill-over effects, with participants promoting mammography and navigation resources to social network members. Future studies should expand research on dosage and its effects, beyond individual-level outcomes, to expand the intervention impacts on cancer health. Mariana Tellez, Ezra B. Wright, Elizabeth de la Paz, Juanita Arroyo, Silvia Montoya, Jocelyn Perez-Ahlgrain, Tatiana Lopez, Irlanda Estrada Sanchez, Heidi Parra, Karyme Huerta, Viviana Bahena, Sheryl Lawrence, Celeste Charchalac-Zapeta, Melissa Martinez, Emely Moreno, Monica Padilla, Candyce H. Kroenke, Garth H. Rauscher, Erin I. Neuschler, Pamela H. Ganschow, Nathan J. Stackhouse, Jennifer Watling Neal, Araceli Lucio, Yamile Molina. Exploring intervention dosage and participant-driven mammography promotion: Early findings from the MADRE study [abstract]. In: Proceedings of the 19th AACR Conference on the Science of Cancer Health Disparities; 2026 Oct 18-21; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2026;35(10 Suppl):Abstract nr A040.