Return of research results to participants in longitudinal cohort studies in health research

Background

Returning research results to participants is increasingly recognised as part of participant-centred health research, yet how this is implemented in cohort studies remains largely undescribed. This study provides a descriptive overview of current result return practices across diverse cohort studies in the Netherlands.

Methods

Drawing on the Amsterdam Cohort Hub, an infrastructure of population-based and patient-based cohorts in the Netherlands, representatives of 24 affiliated cohort studies completed a structured questionnaire administered via individual interviews. The questionnaire covered what results are returned, to whom, when, and how. Individual-level and group-level return were distinguished. Cohorts also reported on motivations for returning results and barriers encountered in doing so. Data were summarised descriptively using frequencies.

Results

Individual-level results beyond incidental findings were returned by 14 cohorts (58%), while group-level results were returned by 23 cohorts (96%). Individual-level return primarily involved physical and laboratory measures or was embedded in routine clinical care. Group-level results were mainly shared through newsletters. Limited resources were reported as a barrier by 15 cohorts (65%) and concerns about participant misinterpretation by 14 cohorts (61%).

Conclusions

Return of research results is widely practiced across cohort studies but varies considerably in approach, shaped by ethical considerations, practical constraints, and available resources. Individual-level and group-level return follow different logics and require different expertise and infrastructure. Taken together, this overview offers cohorts a practical reference for reflecting on their own result return practices. Our findings highlight a structural gap between growing expectations for participant-centred research and the resources and guidance available to support it in cohort settings.

Key messages

• Return of research results is widely practiced in cohort studies but varies considerably, shaped by cohort type, clinical context, and available resources.

• Limited funding and communication complexity are key barriers, highlighting the need for shared guidance and dedicated support for result return in cohort research.