Hi Elisabeth.

Usually in small cohort studies ( n=1 to 200) the feedback is given to the participants by making phone calls and sending text messages (if you have access to that info). If your sample size if bigger than 200 individuals, the preferred way to communicate is usually by email and text messaging.

If the study is longitudinal and living (still recruiting), then your sample size is probably gonna be even bigger than 500, in which case you better set up certain center(s) in the vicinity of the participants so that they will be able to continuously communicate with you and your team members and get feedback if needed. They can actually help you to spread the message for attending to the check-up center and receive their feedback if the study setting is in suburban or rural areas.

You can also check the following link for further information with this regard:

Article Cohort Profile: The Golestan Cohort Studya prospective study...

I hope this helps.

Be safe.

I was a subject in a large clinical trial , n approximately 25, 000 over a 5year period with some further follow-up. This was the VITAL study. They published a monthly 4 page newsletter that did a remarkable job of keeping us informed on how and what was happening in the study. If you Google VITAL study I expect you could find examples of the newsletter. I really recommend it. Even if your studies are much smaller than that just seeing what those researchers did would be really informative. Good luck, David Booth

Hi Elisabeth. Take a look at EUPATI guidance (other valuable resources available at the website): https://eupati.eu/resources/patient-engagement-roadmap/

Hope this helps.