# Closing the loop: Benefits and challenges of sharing clinical trial results with participants after trial close-out

## TL;DR

This study explores how to share clinical trial results with participants after the trial ends, finding that most want to know the results and prefer online summaries.

## Contribution

The study provides insights into participant preferences for receiving trial results and highlights the feasibility of post-trial communication.

## Key findings

- 95.5% of participants wanted to know the trial results.
- Most preferred receiving results via online summary posters.
- Learning results increased future trial participation likelihood for 51% of participants.

## Abstract

Clinical trial participants have a right to know the results of the trials in which they participate. Trial results are often not shared directly with participants and concerns with privacy and resource constraints may prevent researchers from contacting participants after trial completion.

The objectives of this cross-sectional study were to explore the feasibility of contacting orthopaedic fracture trial participants after trial completion and to determine the preferences and priorities of the participants who wished to know the results.

Following the publication of the primary manuscript, we attempted to contact participants from the completed PREPARE trial at Hamilton Health Sciences to determine if they would like to know the trial results. We asked participants about their preferences for receiving trial results, their experiences upon learning them, and if they wished to learn which treatment they received.

Twenty-eight percent (181/641) of PREPARE trial participants contacted agreed to participate in this study. We found that 95.5% (95% CI 91.0%—97.9%) of respondents wished to know the trial results and the preferred method was through viewing summary posters via an online link (78.2%; 95% CI 71.1%—84.0%). Most felt satisfied after learning the trial results (67.8%; 95% CI 59.5%- 75.2%) and 82.2% (95% CI 75.2%—87.5%) wanted to know which treatment they received. Fifty-one percent (95% CI 42.7%—58.7%) reported that learning the results increased their likelihood of participating in a future trial.

Although it was challenging to both contact and re-engage participants after completing an orthopaedic trial that involved minimal participant burden, our study findings suggest that learning the trial results may have a positive impact on individual participants and the research community. Given the limited understanding of results among our respondents, researchers should have processes in place to engage participants meaningfully throughout the trial and proactively discuss with them how the results will be shared once the trial is complete.

IV.

The online version contains supplementary material available at 10.1186/s12874-026-02787-3.