Retention and Structural Inequities in Clinical Research: Insights from a Breastfeeding Intervention Study

Objective. To be effective and generalizable, research must include diverse populations representative of the intended beneficiaries. Among women with low income in the United States, 74.9% initiate breastfeeding, but only 47.5% continue to six months. This analysis examined how structural inequities, indicated by income, race, and ethnicity, affect participant retention in a breastfeeding intervention. Methods. Participants (N=250) enrolled in PROMPT, a longitudinal randomized text-based breastfeeding self-management intervention trial. Cox proportional hazards models were used to analyze retention over 24 weeks. Results. Overall retention was 72%. Dropout risk was significantly higher among Hispanic and non-Hispanic Black participants (HR 2.86, p<.001), and among those with lower income (HR 2.61, p<.001). A three-factor model (including income, race/ethnicity, and age) was statistically significant overall (p=.0001), though individual predictors were not. Conclusion. Structural inequities may contribute to differential retention in breastfeeding trials, highlighting the need for equity-focused recruitment and retention strategies.