Motivation through feedback: the role of returning results to participants in engaging mothers in a birth cohort study

Although cohort studies are essential for understanding health outcomes over time, they often face challenges in participant retention, particularly in contexts of social vulnerability. The return of results to participants has emerged as an ethical and methodological strategy capable of strengthening the bond with participants and reducing loss to follow-up. This article presents the experience of the birth cohort conducted by the Brazilian Center for Early Child Development (CPAPI), in which a Satisfaction Questionnaire was administered to mothers participating in the six-month follow-up stage. The findings identify individual feedback as the primary motivating factor for participants to remain in the study. However, standardized guidelines for institutionalizing this practice are still lacking. We argue that the return of results, beyond being an ethical commitment established in regulatory frameworks, can serve as an effective tool for participant retention in longitudinal studies. Thus, it contributes to the quality and legitimacy of scientific production.