Retrospective observational study applying reinforcement learning and behavioral science to mammography: insights for equitable preventive care

Background In the United States, underserved women face persistent healthcare disparities, making mammography screening and equity public health priorities. Purpose This retrospective observational study assessed how tailored messaging influenced mammogram scheduling and attendance, determined which message types were most effective, and explored differences across key demographic subgroups. Methods We employed Precision Nudging using reinforcement learning and behavioral science to tailor email messages informed by the Capability, Opportunity—Behavior (COM-B) model. Messages were sent to 156 954 women overdue for screening. Mammogram scheduling and attendance were documented via electronic health records. Analyses focused on the engaged patient population who opened at least one email (N = 106 616; 67.9%). Logistic regressions examined whether COM-B content in the first and last message predicted scheduling and attendance, testing interactions for age, race, income, insurance, and education. Results Among engaged patients, 23.7% scheduled and 20.3% attended a mammogram. Capability-focused messaging was generally associated with higher overall uptake, while opportunity messaging consistently predicted lower scheduling and attendance rates. Equity analyses revealed nuanced engagement patterns among underserved groups. Underrepresented racial/ethnic minority women had higher odds of completing screening than White women. Older age predicted lower attendance, with early messages addressing motivation predicting lower attendance than capability messages. Final intervention messages addressing motivation were more effective for low- and high-income women than middle-income women and more effective for women without private insurance. Conclusions These findings suggest that tailoring messages to patients’ needs and context encourages mammogram uptake and may help reduce disparities in women’s health.